diff --git a/.github/dependabot.yml b/.github/dependabot.yml
index 1cbbff45705a..1fad6d5d1194 100644
--- a/.github/dependabot.yml
+++ b/.github/dependabot.yml
@@ -5,7 +5,7 @@ registries:
     type: docker-registry
     url: ghcr.io
     username: PAT
-    password: ${{secrets.CONTAINER_BUILDER_TOKEN}}
+    password: ${{secrets.BASE_CONTAINER_IMAGE_READER_DEPENDABOT}}
 
 updates:
   - package-ecosystem: npm
diff --git a/Dockerfile b/Dockerfile
index d721a58d3e73..d3a34d67428f 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -8,7 +8,7 @@
 # ---------------------------------------------------------------
 # To update the sha:
 # https://github.com/github/gh-base-image/pkgs/container/gh-base-image%2Fgh-base-noble
-FROM ghcr.io/github/gh-base-image/gh-base-noble:20250709-201453-g6a417ef5f AS base
+FROM ghcr.io/github/gh-base-image/gh-base-noble:20250711-151843-g9ff1d29c5 AS base
 
 # Install curl for Node install and determining the early access branch
 # Install git for cloning docs-early-access & translations repos
diff --git a/content/actions/how-tos/writing-workflows/choosing-what-your-workflow-does/using-environments-for-deployment.md b/content/actions/concepts/workflows-and-actions/deployment-environments.md
similarity index 54%
rename from content/actions/how-tos/writing-workflows/choosing-what-your-workflow-does/using-environments-for-deployment.md
rename to content/actions/concepts/workflows-and-actions/deployment-environments.md
index f8151e40784a..70c4bd56667b 100644
--- a/content/actions/how-tos/writing-workflows/choosing-what-your-workflow-does/using-environments-for-deployment.md
+++ b/content/actions/concepts/workflows-and-actions/deployment-environments.md
@@ -1,27 +1,18 @@
 ---
-title: Using environments for deployment
-shortTitle: Environments
-intro: Specify a deployment environment in your workflow.
+title: Deployment environments
+intro: 'You can create and deploy to different environments.'
 versions:
   fpt: '*'
   ghes: '*'
   ghec: '*'
-redirect_from:
-  - /actions/using-jobs/using-environments-for-jobs
-  - /actions/using-jobs/using-environments-for-deployment
-  - /actions/writing-workflows/choosing-what-your-workflow-does/using-environments-for-deployment
+type: overview
+topics:
+  - Actions
+  - Workflows
 ---
- 
-{% data reusables.actions.enterprise-github-hosted-runners %}
-
-## About environments
 
 {% data reusables.actions.about-environments %}
 
 Each job in a workflow can reference a single environment. Any protection rules configured for the environment must pass before a job referencing the environment is sent to a runner. The job can access the environment's secrets only after the job is sent to a runner.
 
 When a workflow references an environment, the environment will appear in the repository's deployments. For more information about viewing current and previous deployments, see [AUTOTITLE](/actions/deployment/managing-your-deployments/viewing-deployment-history).
-
-## Using an environment in a workflow
-
-{% data reusables.actions.environment-example %}
diff --git a/content/actions/concepts/workflows-and-actions/index.md b/content/actions/concepts/workflows-and-actions/index.md
index 22ff6eb4b294..5047b9b11f97 100644
--- a/content/actions/concepts/workflows-and-actions/index.md
+++ b/content/actions/concepts/workflows-and-actions/index.md
@@ -13,6 +13,7 @@ children:
   - /about-custom-actions
   - /contexts
   - /expressions
+  - /deployment-environments
   - /dependency-caching
   - /about-monitoring-workflows
   - /notifications-for-workflow-runs
diff --git a/content/actions/how-tos/writing-workflows/choosing-what-your-workflow-does/deploying-to-a-specific-environment.md b/content/actions/how-tos/writing-workflows/choosing-what-your-workflow-does/deploying-to-a-specific-environment.md
new file mode 100644
index 000000000000..c61b07c0de5f
--- /dev/null
+++ b/content/actions/how-tos/writing-workflows/choosing-what-your-workflow-does/deploying-to-a-specific-environment.md
@@ -0,0 +1,44 @@
+---
+title: Deploying to a specific environment
+shortTitle: Deploy to environment
+intro: Specify a deployment environment in your workflow.
+versions:
+  fpt: '*'
+  ghes: '*'
+  ghec: '*'
+redirect_from:
+  - /actions/using-jobs/using-environments-for-jobs
+  - /actions/using-jobs/using-environments-for-deployment
+  - /actions/writing-workflows/choosing-what-your-workflow-does/using-environments-for-deployment
+  - /actions/how-tos/writing-workflows/choosing-what-your-workflow-does/using-environments-for-deployment
+---
+
+## Prerequisites
+
+You need to create an environment before you can use it in a workflow. See [AUTOTITLE](/actions/how-tos/managing-workflow-runs-and-deployments/managing-deployments/managing-environments-for-deployment#creating-an-environment).
+
+## Using an environment in a workflow
+
+1. Open the workflow file you want to edit.
+1. Use the following syntax to add a [`jobs.<job_id>.environment`](/actions/using-workflows/workflow-syntax-for-github-actions#jobsjob_idenvironment) key to your workflow:
+
+    ```yaml copy
+    jobs:
+      JOB-ID:
+        environment: ENVIRONMENT-NAME
+    ```
+
+    The chosen job will now be subject to any rules configured for the specified environment.
+1. Optionally, specify a deployment URL for the environment using the following syntax:
+
+    ```yaml copy
+    jobs:
+      JOB-ID:
+        environment: ENVIRONMENT-NAME
+        url: URL
+    ```
+
+    The specified URL will appear:
+    * On the deployments page for the repository
+    * In the visualization graph for the workflow run
+    * (If a pull request triggers the workflow) As a "View deployment" button in the pull request timeline
diff --git a/content/actions/how-tos/writing-workflows/choosing-what-your-workflow-does/index.md b/content/actions/how-tos/writing-workflows/choosing-what-your-workflow-does/index.md
index 93bea44eef14..0ef0ad1a2b33 100644
--- a/content/actions/how-tos/writing-workflows/choosing-what-your-workflow-does/index.md
+++ b/content/actions/how-tos/writing-workflows/choosing-what-your-workflow-does/index.md
@@ -18,7 +18,7 @@ children:
   - /store-information-in-variables
   - /passing-information-between-jobs
   - /setting-a-default-shell-and-working-directory
-  - /using-environments-for-deployment
+  - /deploying-to-a-specific-environment
   - /control-the-concurrency-of-workflows-and-jobs
   - /running-variations-of-jobs-in-a-workflow
   - /storing-and-sharing-data-from-a-workflow
diff --git a/content/contributing/setting-up-your-environment-to-work-on-github-docs/creating-a-local-environment.md b/content/contributing/setting-up-your-environment-to-work-on-github-docs/creating-a-local-environment.md
index 9f0d16386540..178824fd2b6e 100644
--- a/content/contributing/setting-up-your-environment-to-work-on-github-docs/creating-a-local-environment.md
+++ b/content/contributing/setting-up-your-environment-to-work-on-github-docs/creating-a-local-environment.md
@@ -74,7 +74,7 @@ For example, to enable Japanese and Portuguese in addition to English, you can e
 > [!NOTE]
 > Before you commit your changes, you should revert the `package.json` file to its original state.
 
-The supported language codes are defined in [`src/languages/lib/languages.js`](https://github.com/github/docs/blob/main/src/languages/lib/languages.js).
+The supported language codes are defined in [`src/languages/lib/languages.ts`](https://github.com/github/docs/blob/main/src/languages/lib/languages.ts).
 
 ## Using {% data variables.product.prodname_github_codespaces %}
 
diff --git a/content/contributing/writing-for-github-docs/configuring-redirects.md b/content/contributing/writing-for-github-docs/configuring-redirects.md
index 9036cd4f3d4f..03c3810c6a8b 100644
--- a/content/contributing/writing-for-github-docs/configuring-redirects.md
+++ b/content/contributing/writing-for-github-docs/configuring-redirects.md
@@ -38,7 +38,7 @@ See [`redirect_from`](https://github.com/github/docs/blob/main/content/README.md
 
 If a URL for a page is entered without a version (`https://docs.github.com/ARTICLE` instead of `https://docs.github.com/VERSION/ARTICLE`), the site will automatically redirect it to the first available version of the page.<!-- markdownlint-disable-line search-replace -->
 
-The order of precedence is specified in [`lib/all-versions.js`](https://github.com/github/docs/blob/main/src/versions/lib/all-versions.js). The current order of precedence is:
+The order of precedence is specified in [`lib/all-versions.ts`](https://github.com/github/docs/blob/main/src/versions/lib/all-versions.ts). The current order of precedence is:
 
 1. {% data variables.product.prodname_free_team %}, {% data variables.product.prodname_pro %}, or {% data variables.product.prodname_team %} (`fpt`)
 1. {% data variables.product.prodname_ghe_cloud %} (`ghec`)
diff --git a/content/contributing/writing-for-github-docs/using-yaml-frontmatter.md b/content/contributing/writing-for-github-docs/using-yaml-frontmatter.md
index 33edfed2f65f..59fcf89afd41 100644
--- a/content/contributing/writing-for-github-docs/using-yaml-frontmatter.md
+++ b/content/contributing/writing-for-github-docs/using-yaml-frontmatter.md
@@ -46,7 +46,7 @@ For more information, see [`lib/frontmatter.js`](https://github.com/github/docs/
 
 ### `versions`
 
-* Purpose: Indicates the [versions](https://github.com/github/docs/blob/main/src/versions/lib/all-versions.js) to which a page applies.
+* Purpose: Indicates the [versions](https://github.com/github/docs/blob/main/src/versions/lib/all-versions.ts) to which a page applies.
 For more information about the different types of versioning, see [Versioning documentation](/contributing/syntax-and-versioning-for-github-docs/versioning-documentation).
 * Type: `Object`. Allowable keys map to product names and can be found in the `versions` object in [`lib/frontmatter.js`](https://github.com/github/docs/blob/main/src/frame/lib/frontmatter.js).
 * This frontmatter value is currently **required** for all pages.
diff --git a/content/copilot/get-started/github-copilot-features.md b/content/copilot/get-started/github-copilot-features.md
index 337da2978722..c0caf0037053 100644
--- a/content/copilot/get-started/github-copilot-features.md
+++ b/content/copilot/get-started/github-copilot-features.md
@@ -57,7 +57,7 @@ AI-generated text completion to help you write pull request descriptions quickly
 
 Enhance {% data variables.copilot.copilot_chat_short %} responses by providing contextual details on your preferences, tools, and requirements. See [AUTOTITLE](/copilot/customizing-copilot/about-customizing-github-copilot-chat-responses).
 
-### {% data variables.copilot.copilot_desktop_short %} ({% data variables.release-phases.public_preview %})
+### {% data variables.copilot.copilot_desktop_short %}
 
 Automatically generate commit messages and descriptions with {% data variables.copilot.copilot_desktop_short %} based on the changes you make to your project.
 
diff --git a/content/copilot/how-tos/administer/enterprises/managing-policies-and-features-for-copilot-in-your-enterprise.md b/content/copilot/how-tos/administer/enterprises/managing-policies-and-features-for-copilot-in-your-enterprise.md
index 854fab8e7ee9..9bd8202e77ba 100644
--- a/content/copilot/how-tos/administer/enterprises/managing-policies-and-features-for-copilot-in-your-enterprise.md
+++ b/content/copilot/how-tos/administer/enterprises/managing-policies-and-features-for-copilot-in-your-enterprise.md
@@ -30,7 +30,7 @@ You can configure policies for your enterprise. If no policy is chosen at the en
 | ----------- | ------------------------------------------ |
 | [{% data variables.product.prodname_copilot_short %} in {% data variables.product.prodname_dotcom_the_website %}](#copilot-in-githubcom) | least restrictive |
 | [{% data variables.copilot.copilot_cli %}](#github-copilot-in-the-cli) | least restrictive |
-| [{% data variables.copilot.copilot_desktop_short %} ({% data variables.release-phases.public_preview %})](#copilot-in-github-desktop-public-preview) | least restrictive |
+| [{% data variables.copilot.copilot_desktop_short %}](#copilot-in-github-desktop) | least restrictive |
 | [{% data variables.copilot.copilot_chat %} in the IDE](#github-copilot-chat-in-the-ide) | least restrictive |
 | [Editor preview features](#editor-preview-features) | least restrictive |
 | [{% data variables.copilot.copilot_mobile %}](#github-copilot-chat-in-github-mobile) | least restrictive |
@@ -57,7 +57,7 @@ If you enable "{% data variables.product.prodname_copilot_short %} in {% data va
 
 {% data variables.copilot.copilot_cli %} is an extension for {% data variables.product.prodname_cli %} which provides a chat-like interface in the terminal. You can ask {% data variables.product.prodname_copilot %} for command suggestions, or for explanations of commands they run.
 
-### {% data variables.copilot.copilot_desktop_short %} ({% data variables.release-phases.public_preview %})
+### {% data variables.copilot.copilot_desktop_short %}
 
 You can generate commit messages and descriptions in {% data variables.product.prodname_desktop %} based on the changes you make to your project.
 
diff --git a/content/copilot/how-tos/administer/organizations/managing-policies-for-copilot-in-your-organization.md b/content/copilot/how-tos/administer/organizations/managing-policies-for-copilot-in-your-organization.md
index 159544004ff9..7859ae8bb4fb 100644
--- a/content/copilot/how-tos/administer/organizations/managing-policies-for-copilot-in-your-organization.md
+++ b/content/copilot/how-tos/administer/organizations/managing-policies-for-copilot-in-your-organization.md
@@ -33,11 +33,11 @@ Organization owners can set policies to govern how {% data variables.product.pro
   * Image support in {% data variables.copilot.copilot_chat_short %} (available in {% data variables.product.prodname_vscode_shortname %} and {% data variables.product.prodname_vs %})
     >[!NOTE] This setting only applies to preview features within {% data variables.product.prodname_copilot_short %} and does not control all preview-related settings in {% data variables.product.prodname_vscode_shortname %}.
 * {% data variables.copilot.copilot_coding_agent %} ({% data variables.release-phases.public_preview %})
-* {% data variables.copilot.copilot_spaces %} (public preview)
+* {% data variables.copilot.copilot_spaces %} ({% data variables.release-phases.public_preview %})
 * MCP servers on {% data variables.product.prodname_dotcom_the_website %} ({% data variables.release-phases.public_preview %})
 * {% data variables.copilot.copilot_mobile_short %}
 * {% data variables.copilot.copilot_cli_short %} and {% data variables.product.prodname_windows_terminal %}
-* {% data variables.copilot.copilot_desktop_short %} ({% data variables.release-phases.public_preview %})
+* {% data variables.copilot.copilot_desktop_short %}
 * Suggestions matching public code
 * Access to alternative models for {% data variables.product.prodname_copilot_short %}
   * Anthropic {% data variables.copilot.copilot_claude %} in {% data variables.product.prodname_copilot_short %}
@@ -65,7 +65,7 @@ If an organization member is assigned a seat by multiple organizations with diff
 
    For example, to enable or disable suggestion matching, in the "Suggestions matching public code" dropdown, select **Allowed** or **Blocked**.
 
-1. If your organization has a {% data variables.copilot.copilot_business_short %}{% ifversion ghec %} or {% data variables.copilot.copilot_enterprise_short %}{% endif %} plan and you enable "{% data variables.product.prodname_copilot_short %} in {% data variables.product.prodname_dotcom_the_website %}", two additional options are displayed:
+1. If your organization has a {% data variables.copilot.copilot_business_short %}{% ifversion ghec %} or {% data variables.copilot.copilot_enterprise_short %}{% endif %} plan and you enable "{% data variables.product.prodname_copilot_short %} in {% data variables.product.prodname_dotcom_the_website %}," two additional options are displayed:
 
     {% data reusables.copilot.policies-for-dotcom %}
 
diff --git a/content/copilot/how-tos/custom-instructions/adding-repository-custom-instructions-for-github-copilot.md b/content/copilot/how-tos/custom-instructions/adding-repository-custom-instructions-for-github-copilot.md
index 9ce1b511a9de..fd994b5f9ff8 100644
--- a/content/copilot/how-tos/custom-instructions/adding-repository-custom-instructions-for-github-copilot.md
+++ b/content/copilot/how-tos/custom-instructions/adding-repository-custom-instructions-for-github-copilot.md
@@ -238,7 +238,7 @@ You can create a custom instructions file in your repository via the {% data var
 Whitespace between instructions is ignored, so the instructions can be written as a single paragraph, each on a new line, or separated by blank lines for legibility.
 
 1. Open the {% data variables.product.prodname_copilot %} for Xcode application.
-1. At the top of the application window, click **Advanced**.
+1. At the top of the application window, under **Settings**, click **Advanced**.
 1. To the right of "Custom Instructions", click **Current Workspace** or **Global** to choose whether the custom instructions apply to the current workspace or all workspaces.
 
 {% endxcode %}
diff --git a/content/desktop/making-changes-in-a-branch/committing-and-reviewing-changes-to-your-project-in-github-desktop.md b/content/desktop/making-changes-in-a-branch/committing-and-reviewing-changes-to-your-project-in-github-desktop.md
index b29ba610d0ba..d4a63b92c839 100644
--- a/content/desktop/making-changes-in-a-branch/committing-and-reviewing-changes-to-your-project-in-github-desktop.md
+++ b/content/desktop/making-changes-in-a-branch/committing-and-reviewing-changes-to-your-project-in-github-desktop.md
@@ -24,7 +24,7 @@ Repository administrators can enable rulesets for a branch to enforce specific c
 
 1. [Create a new branch](/desktop/making-changes-in-a-branch/managing-branches-in-github-desktop), or select an existing branch by clicking **{% octicon "git-branch" aria-hidden="true" aria-label="git-branch" %} Current Branch** on the toolbar and selecting the branch from the list.
 
-   ![Screenshot of the "Current Branch" dropdown view. Under "Recent Branches", a branch, named "my-feature", is highlighted with an orange outline.](/assets/images/help/desktop/select-branch-from-dropdown.png)
+   ![Screenshot of the "Current Branch" dropdown view. Under "Recent Branches," a branch, named "my-feature," is highlighted with an orange outline.](/assets/images/help/desktop/select-branch-from-dropdown.png)
 {% data reusables.desktop.make-changes %}
 
 ## Choosing how to display diffs
@@ -32,7 +32,7 @@ Repository administrators can enable rulesets for a branch to enforce specific c
 You can change the way diffs are displayed in {% data variables.product.prodname_desktop %} to suit your reviewing needs.
 
 To change how you view diffs, in the top-right corner of the diff view, click {% octicon "gear" aria-label="The Gear icon" %}.
-* To change how the entire diff is displayed, under "Diff display", select **Unified** or **Split**. The Unified view shows changes linearly, while the Split view shows old content on the left side and new content on the right side.
+* To change how the entire diff is displayed, under "Diff display," select **Unified** or **Split**. The Unified view shows changes linearly, while the Split view shows old content on the left side and new content on the right side.
 * To hide whitespace changes so you can focus on more substantive changes, select **Hide Whitespace Changes**.
 
 ![Screenshot of the diff view of a file. A gear icon is outlined in orange and expanded to display "Whitespace" and "Diff display" settings.](/assets/images/help/desktop/diff-selection.png)
@@ -43,7 +43,7 @@ If you need to see more of the file than {% data variables.product.prodname_desk
 * To see the next few lines above or below the highlighted changes, click the arrow above or below the line numbers.
 * To see the entire file, right-click in the diff view and click **Expand Whole File**.
 
-![Screenshot of the diff view of a "README" file. Over a green "addition" line, in a context menu, the cursor hovers over "Expand Whole File".](/assets/images/help/desktop/expand-diff-view.png)
+![Screenshot of the diff view of a "README" file. Over a green "addition" line, in a context menu, the cursor hovers over "Expand Whole File."](/assets/images/help/desktop/expand-diff-view.png)
 
 ## Selecting changes to include in a commit
 
@@ -57,7 +57,7 @@ In the "Changes" tab in the left sidebar:
 * To access stashed changes, click **Stashed Changes**.
 * {% data reusables.desktop.commit-all-desc %}
 
-  ![Screenshot of the "Changes" tab. Above the list of changed files, next to the text "3 changed files", a selected checkbox is outlined in orange.](/assets/images/help/desktop/commit-all.png)
+  ![Screenshot of the "Changes" tab. Above the list of changed files, next to the text "3 changed files," a selected checkbox is outlined in orange.](/assets/images/help/desktop/commit-all.png)
 * {% data reusables.desktop.commit-some-desc %}
 
 ### Creating a partial commit
@@ -79,7 +79,7 @@ Discarded changes are saved in a dated file in the Trash. You can recover discar
 {% data reusables.desktop.select-discard-files %}
 {% data reusables.desktop.click-discard-files %}
 
-   ![Screenshot of the "Changes" tab. Two selected files are highlighted in blue. In a context menu, the cursor hovers over "Discard 2 Selected Changes".](/assets/images/help/desktop/discard-changes-mac.png)
+   ![Screenshot of the "Changes" tab. Two selected files are highlighted in blue. In a context menu, the cursor hovers over "Discard 2 Selected Changes."](/assets/images/help/desktop/discard-changes-mac.png)
 {% data reusables.desktop.confirm-discard-files %}
 
 ### Discarding changes in one or more lines
@@ -91,7 +91,7 @@ You can discard one or more changed lines that are uncommitted.
 
 To discard one added line, in the list of changed lines, right-click the line number of the line you want to discard, then select **Discard Added Line**.
 
-![Screenshot of the diff view of a file. In a context menu, a cursor hovers over "Discard Added Line", highlighted in blue.](/assets/images/help/desktop/discard-single-line.png)
+![Screenshot of the diff view of a file. In a context menu, a cursor hovers over "Discard Added Line," highlighted in blue.](/assets/images/help/desktop/discard-single-line.png)
 
 To discard a group of changed lines, right-click the vertical bar to the right of the line numbers for the lines you want to discard, then select **Discard added lines**.
 
@@ -105,7 +105,8 @@ Once you're satisfied with the changes you've chosen to include in your commit,
 > {% data reusables.desktop.tags-push-with-commits %} For more information, see [AUTOTITLE](/desktop/managing-commits/managing-tags-in-github-desktop).
 
 1. At the bottom of the list of changes, next to your profile picture, describe your commit:
-   * If you have access to {% data variables.product.prodname_copilot %} and you are using [{% data variables.product.prodname_desktop %} beta](https://desktop.github.com/beta/), you can automatically create a commit message and details based on the changes you made. Click {% octicon "copilot" aria-label="Generate commit message with Copilot" %}.
+   * If you have access to {% data variables.product.prodname_copilot %}, you can automatically create a commit message and details based on the changes you made. Click {% octicon "copilot" aria-label="Generate commit message with Copilot" %}.
+   * If you want to regenerate a different commit message, click {% octicon "copilot" aria-label="Regenerate commit message with Copilot" %} again to generate a new suggestion.
    * Alternatively, type your own short, meaningful commit message in the Summary field. You can also add more information about the change in the Description field.
 
    ![Screenshot of the "Changes" tab. The "Summary" field and "Generate commit message with Copilot" button are outlined in orange.](/assets/images/help/desktop/create-commit-details.png)
@@ -125,7 +126,7 @@ Once you're satisfied with the changes you've chosen to include in your commit,
 
    If a pull request has not been created for the current branch, {% data variables.product.prodname_desktop %} will give you the option to preview the changes and create one. For more information, see [AUTOTITLE](/desktop/working-with-your-remote-repository-on-github-or-github-enterprise/creating-an-issue-or-pull-request-from-github-desktop).
 
-   ![Screenshot of the "No local changes" view. A button, labeled "Preview Pull Request", is highlighted with an orange outline.](/assets/images/help/desktop/mac-preview-pull-request.png)
+   ![Screenshot of the "No local changes" view. A button, labeled "Preview Pull Request," is highlighted with an orange outline.](/assets/images/help/desktop/mac-preview-pull-request.png)
 
 ## Managing your commit history
 
diff --git a/src/content-render/unified/rewrite-local-links.js b/src/content-render/unified/rewrite-local-links.js
index ee297d85db05..795abd0605b8 100644
--- a/src/content-render/unified/rewrite-local-links.js
+++ b/src/content-render/unified/rewrite-local-links.js
@@ -1,3 +1,6 @@
+// When updating this file to typescript,
+// update links in content/contributing as well
+
 import path from 'path'
 
 import stripAnsi from 'strip-ansi'
diff --git a/src/frame/lib/frontmatter.js b/src/frame/lib/frontmatter.js
index bb8dddd9ce61..9d12b7049709 100644
--- a/src/frame/lib/frontmatter.js
+++ b/src/frame/lib/frontmatter.js
@@ -1,3 +1,6 @@
+// when updating to typescript,
+// update links in content/contributing as well
+
 import parse from './read-frontmatter'
 import { allVersions } from '@/versions/lib/all-versions'
 import { allTools } from '@/tools/lib/all-tools'
diff --git a/src/shielding/middleware/handle-malformed-urls.ts b/src/shielding/middleware/handle-malformed-urls.ts
new file mode 100644
index 000000000000..a785864e5069
--- /dev/null
+++ b/src/shielding/middleware/handle-malformed-urls.ts
@@ -0,0 +1,31 @@
+import type { Response, NextFunction } from 'express'
+
+import { defaultCacheControl } from '@/frame/middleware/cache-control'
+import { ExtendedRequest } from '@/types'
+
+/**
+ * Middleware to handle malformed UTF-8 sequences in URLs that cause
+ * decodeURIComponent to fail. This prevents crashes from malicious
+ * requests containing invalid URL-encoded sequences like %FF.
+ */
+export default function handleMalformedUrls(
+  req: ExtendedRequest,
+  res: Response,
+  next: NextFunction,
+) {
+  // Check URL for malformed UTF-8 sequences
+  // Express/router doesn't catch these during initial parsing - they cause
+  // crashes later when decodeURIComponent is called at the router level
+  const url = req.originalUrl || req.url
+  try {
+    decodeURIComponent(url)
+  } catch {
+    // If any decoding fails, this is a malformed URL
+    defaultCacheControl(res)
+    res.setHeader('content-type', 'text/plain')
+    res.status(400).send('Bad Request: Malformed URL')
+    return
+  }
+
+  return next()
+}
diff --git a/src/shielding/middleware/index.ts b/src/shielding/middleware/index.ts
index a22f952c520d..61af52f9c085 100644
--- a/src/shielding/middleware/index.ts
+++ b/src/shielding/middleware/index.ts
@@ -1,5 +1,6 @@
 import express from 'express'
 
+import handleMalformedUrls from './handle-malformed-urls'
 import handleInvalidQuerystrings from './handle-invalid-query-strings'
 import handleInvalidPaths from './handle-invalid-paths'
 import handleOldNextDataPaths from './handle-old-next-data-paths'
@@ -9,6 +10,7 @@ import handleInvalidHeaders from './handle-invalid-headers'
 
 const router = express.Router()
 
+router.use(handleMalformedUrls)
 router.use(handleInvalidQuerystrings)
 router.use(handleInvalidPaths)
 router.use(handleOldNextDataPaths)
diff --git a/src/shielding/tests/malformed-urls.ts b/src/shielding/tests/malformed-urls.ts
new file mode 100644
index 000000000000..9262e707f084
--- /dev/null
+++ b/src/shielding/tests/malformed-urls.ts
@@ -0,0 +1,72 @@
+import { describe, expect, test } from 'vitest'
+import { get } from '@/tests/helpers/e2etest'
+
+describe('malformed URLs', () => {
+  test('blocks URLs with %FF sequences', async () => {
+    const res = await get('/en/site-policy/other-site-policies/github-account-%FFqrlkuciqll-policy')
+
+    expect(res.statusCode).toBe(400)
+    expect(res.headers['content-type']).toMatch('text/plain')
+    expect(res.body).toBe('Bad Request: Malformed URL')
+  })
+
+  test('blocks URLs with %FE sequences', async () => {
+    const res = await get('/en/some-page-%FE-test')
+    expect(res.statusCode).toBe(400)
+    expect(res.headers['content-type']).toMatch('text/plain')
+    expect(res.body).toBe('Bad Request: Malformed URL')
+  })
+
+  test('blocks URLs with overlong encoding %C0%80', async () => {
+    const res = await get('/en/test-%C0%80-page')
+    expect(res.statusCode).toBe(400)
+    expect(res.headers['content-type']).toMatch('text/plain')
+    expect(res.body).toBe('Bad Request: Malformed URL')
+  })
+
+  test('blocks URLs with invalid UTF-8 continuation sequences', async () => {
+    const res = await get('/en/test-%80%80-page')
+    expect(res.statusCode).toBe(400)
+    expect(res.headers['content-type']).toMatch('text/plain')
+    expect(res.body).toBe('Bad Request: Malformed URL')
+  })
+
+  test('allows URLs with control characters (valid UTF-8)', async () => {
+    const res = await get('/en/test-%01-page')
+    expect(res.statusCode).toBe(404) // Should be 404 since page doesn't exist, not 400
+    // Control characters like %01 are valid UTF-8 and don't cause decoding errors
+  })
+
+  test('allows valid URLs with proper encoding', async () => {
+    const res = await get('/en/get-started')
+    expect(res.statusCode).not.toBe(400)
+    // Should not be blocked by malformed URL middleware
+  })
+
+  test('allows valid URLs with proper percent encoding', async () => {
+    const res = await get('/en/search?q=test%20query')
+    expect(res.statusCode).not.toBe(400)
+    // Should not be blocked by malformed URL middleware
+  })
+
+  test('blocks malformed query parameters', async () => {
+    // This is caught by checking originalUrl which contains the raw, unparsed URL
+    const res = await get('/en/search?q=test%FF')
+    expect(res.statusCode).toBe(400)
+    expect(res.headers['content-type']).toMatch('text/plain')
+    expect(res.body).toBe('Bad Request: Malformed URL')
+  })
+
+  test('properly caches malformed URL responses', async () => {
+    const res = await get('/en/malformed-%FF-url')
+    expect(res.statusCode).toBe(400)
+    expect(res.headers['cache-control']).toBeDefined()
+  })
+
+  test('handles multiple malformed sequences', async () => {
+    const res = await get('/en/test-%FF%FE%80-page')
+    expect(res.statusCode).toBe(400)
+    expect(res.headers['content-type']).toMatch('text/plain')
+    expect(res.body).toBe('Bad Request: Malformed URL')
+  })
+})