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.
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.
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.
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 requests that require user-specific authentication (using cookies or `withCredentials: true`) during the initial server-side render.
* **Shared Caching:** The application's HTML responses must be cached by a shared caching layer (CDN, reverse proxy, or server-side cache) without proper cache-control headers to distinguish authenticated users.
### Patches
- 22.0.0-rc.2
- 21.2.15
- 20.3.22
- 19.2.23
EUVD source date text has no stated timezone and is retained without inventing a UTC instant. Related bulletin membership is not an alias, common cause or applicability claim. A missing vector with a zero score is treated as unrated. Complete vendor/product and underlying source evidence remains in the original JSON.
Original publisher date fields
datePublished: Jun 22, 2026, 3:39:08 PM
dateUpdated: Jun 23, 2026, 4:00:21 PM
No normalized affected-package data is projected for this source revision. The original publisher record may contain additional product and version evidence; this does not establish that a package is unaffected.
NVD analysis and CPE criteria are source context, not proof that a package or your environment is affected. Complete affected data, logical configurations and SSVC are retained in the original JSON.
The original JSON retains the logical configuration operators, exclusions and version bounds.
No normalized affected-package data is projected for this source revision. The original publisher record may contain additional product and version evidence; this does not establish that a package is unaffected.