PT-2026-49561 · Npm · @Angular/Common

Published

2026-06-15

·

Updated

2026-06-15

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CVE-2026-50170

CVSS v4.0

8.2

High

VectorAV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
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

Fix

Found an issue in the description? Have something to add? Feel free to write us 👾
dbugs@ptsecurity.com

Weakness Enumeration

CWE-524

Related Identifiers

CVE-2026-50170
GHSA-Q6F4-QQRG-JV6X

Affected Products

@Angular/Common