CVE-2026-88059 Angular: Information Leak via `HttpTransferCache` Bypass When Using `withRequestsMadeViaParent`
Attackers can access sensitive authenticated data cached in SSR HTML due to improper HttpTransferCache handling in Angular applications.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-88059?
CVE-2026-88059 is a medium-severity vulnerability in angular, published on 10 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Angular is a development platform for building mobile and desktop web applications using TypeScript/JavaScript and other languages. Prior to 20.3.28, 21.2.20, and 22.1.1, Angular's @angular/common HttpTransferCache can cache an authenticated response when Server-Side Rendering (SSR) and hydration use a hierarchical HttpClient configured with withRequestsMadeViaParent. The child TransferCache evaluates an initially anonymous request before delegation, then a parent withInterceptors chain adds an Authorization header, cookie, or API token; although the parent cache skips the authenticated request, the child still stores the private response in TransferState serialized as JSON in the ng-state script. Exploitation requires provideClientHydration, child provideHttpClient delegation through withRequestsMadeViaParent, parent-level credential injection, and an SSR HTML response shared across users by a CDN, reverse proxy, or application cache. A later unauthenticated or unauthorized visitor can receive the cached HTML containing the earlier authenticated user's sensitive response data. Applications can mitigate by attaching credentials at the child, filtering sensitive endpoints with withHttpTransferCacheOptions, disabling transfer caching for sensitive routes, or marking personalized HTML private or no-store. This issue is fixed in versions 20.3.28, 21.2.20, and 22.1.1.
Which versions are affected by CVE-2026-88059?
8 open source packages ship an affected version, including @angular/common. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
@angular/common npm | All versions to 19.2.25 | None |
@angular/common npm | All versions to 19.2.25 | None |
@angular/common npm | From 20.0.0 | 20.3.28 |
@angular/common npm | From 20.0.0 | 20.3.28 |
@angular/common npm | From 21.0.0 | 21.2.20 |
@angular/common npm | From 21.0.0 | 21.2.20 |
2 more packages
@angular/common npm | From 22.0.0 | 22.1.1 |
@angular/common npm | From 22.0.0 | 22.1.1 |
Products include Angular Angular.
How do I fix CVE-2026-88059?
Upgrade @angular/common to a fixed version for your release line: 20.3.28, 21.2.20 or 22.1.1.
Is CVE-2026-88059 being exploited?
There is no known exploitation of CVE-2026-88059 in the wild and no public exploit code.
Other vulnerabilities in angular
- CVE-2026-68945 Angular: Cache-Key Ambiguity in HttpTransferCache Leading to Cross-Request Response Reuse and State Poisoning
- CVE-2026-46417 Angular: SSRF via Hostname Hijacking in @angular/platform-server
- CVE-2026-50168 Angular: URL Parser Differential in @angular/platform-server leading to SSRF Allowlist Bypass
- CVE-2026-54266 Angular: Weak 32-Bit Cache Key Hashing in `HttpTransferCache` Leading to Cross-Request Data Leakage and State Poisoning
- CVE-2026-41423 Angular: SSRF via protocol-relative and backslash URLs in Angular Platform-Server
Sources
Also known as DEBIAN-CVE-2026-88059, GHSA-p297-fm68-3q8c, UBUNTU-CVE-2026-88059.