Angular is a development platform for building mobile and desktop web applications using TypeScript/JavaScript and other languages. Prior to 22.0.0-rc.2, 21.2.15, 20.3.22, and 19.2.23, a vulnerability was discovered in @angular/common when Server-Side Rendering (SSR) and hydration are enabled. The HttpTransferCache utility optimizes hydration by caching outgoing HTTP requests performed during SSR and transferring the cached state to the client-side application via TransferState. However, the caching mechanism fails to inspect the withCredentials flag or the Cookie header of outgoing requests. As a result, credentialed, user-specific responses may be cached by default in the shared TransferState payload. When these responses are serialized into the HTML, any caching layer (such as a CDN, reverse proxy, or shared server cache) that caches the SSR-rendered HTML page could inadvertently cache and leak one user's private data to other users, leading to a high-severity information disclosure vulnerability. This vulnerability is fixed in 22.0.0-rc.2, 21.2.15, 20.3.22, and 19.2.23.

Affected: npm: @angular/common

A vulnerability was discovered in `@angular/common` when Server-Side Rendering (SSR) and hydration are enabled. The `HttpTransferCache` utility optimizes hydration by caching outgoing HTTP requests performed during SSR and transferring the cached state to the client-side application via `TransferState`.

However, the caching mechanism fails to inspect the `withCredentials` flag or the `Cookie` header of outgoing requests. As a result, credentialed, user-specific responses may be cached by default in the shared `TransferState` payload. When these responses are serialized into the HTML, any caching layer (such as a CDN, reverse proxy, or shared server cache) that caches the SSR-rendered HTML page could inadvertently cache and leak one user's private data to other users, leading to a high-severity information disclosure vulnerability.

### Impact

Successful exploitation allows an unauthenticated attacker to obtain sensitive, user-specific information of other authenticated users. This occurs when:

* The SSR-rendered HTML containing the cached private data is stored in a shared cache (e.g., CDN, reverse proxy). * Subsequent requests for the same page receive the cached HTML containing the first user's private data.

### Attack Preconditions

* **SSR and Hydration Enabled:** The Angular application must be configured to use Server-Side Rendering and hydration (e.g., using `provideClientHydration()`). * **Credentialed Requests during SSR:** The application must perform HTTP…

Affected: Ubuntu:Pro:16.04:LTS: angular.js, Ubuntu:Pro:18.04:LTS: angular.js, Ubuntu:Pro:20.04:LTS: angular.js, Ubuntu:22.04:LTS: angular.js, Ubuntu:24.04:LTS: angular.js, Ubuntu:25.10: angular.js, Ubuntu:26.04:LTS: angular.js

Angular is a development platform for building mobile and desktop web applications using TypeScript/JavaScript and other languages. Prior to 22.0.0-rc.2, 21.2.15, 20.3.22, and 19.2.23, a vulnerability was discovered in @angular/common when Server-Side Rendering (SSR) and hydration are enabled. The HttpTransferCache utility optimizes hydration by caching outgoing HTTP requests performed during SSR and transferring the cached state to the client-side application via TransferState. However, the caching mechanism fails to inspect the withCredentials flag or the Cookie header of outgoing requests. As a result, credentialed, user-specific responses may be cached by default in the shared TransferState payload. When these responses are serialized into the HTML, any caching layer (such as a CDN, reverse proxy, or shared server cache) that caches the SSR-rendered HTML page could inadvertently cache and leak one user's private data to other users, leading to a high-severity information disclosure vulnerability. This vulnerability is fixed in 22.0.0-rc.2, 21.2.15, 20.3.22, and 19.2.23.

Ein Angreifer kann mehrere Schwachstellen in Angular ausnutzen, um erweiterte Berechtigungen zu erlangen, beliebigen Code auszuführen, Sicherheitsmaßnahmen zu umgehen, Cross-Site-Scripting-Angriffe durchzuführen, einen Denial-of-Service-Zustand herbeizuführen, Daten zu manipulieren oder offenzulegen, Benutzer auf bösartige Websites umzuleiten oder Sitzungen zu kapern.