CVE-2026-54266 Angular: Weak 32-Bit Cache Key Hashing in `HttpTransferCache` Leading to Cross-Request Data Leakage and State Poisoning
Attackers can exploit weak hashing in Angular's SSR cache to cause collisions, leaking sensitive data or poisoning state via crafted links.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-54266?
CVE-2026-54266 is a high-severity vulnerability in angular, published on 22 Jun 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 22.0.1, 21.2.17, and 20.3.25, Angular's HttpTransferCache caches HTTP requests made during Server-Side Rendering (SSR) so that they can be reused during client-side hydration. This avoids repeating the same HTTP requests on the client. The cached responses are stored in TransferState using a cache key generated by hashing request properties (method, response type, mapped URL, serialized body, and sorted query parameters). The cache keys are generated using a weak 32-bit DJB2-like polynomial rolling hash. The 32-bit hash space is extremely small, allowing attackers to find hash collisions. An attacker can easily find a query parameter string (e.g., q=aaCAZMMM for a search request) that produces the exact same 32-bit hash as a sensitive endpoint (e.g., /api/user/profile). When a victim visits a crafted link containing the colliding parameter, the SSR process executes both the search request and the profile request. Due to the hash collision, the search response overwrites the profile response in the TransferState cache. This vulnerability is fixed in 22.0.1, 21.2.17, and 20.3.25.
Which versions are affected by CVE-2026-54266?
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-next.0 | 20.3.25 |
@angular/common npm | From 20.0.0-next.0 | 20.3.25 |
@angular/common npm | From 21.0.0-next.0 | 21.2.17 |
@angular/common npm | From 21.0.0-next.0 | 21.2.17 |
2 more packages
@angular/common npm | From 22.0.0-next.0 | 22.0.1 |
@angular/common npm | From 22.0.0-next.0 | 22.0.1 |
Products include Angular Angular.
How do I fix CVE-2026-54266?
Upgrade @angular/common to a fixed version for your release line: 20.3.25, 21.2.17 or 22.0.1.
Is CVE-2026-54266 being exploited?
There is no known exploitation of CVE-2026-54266 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-2026-41423 Angular: SSRF via protocol-relative and backslash URLs in Angular Platform-Server
- CVE-2026-88056 Angular: SSRF and Cross-Origin Credential Disclosure via URL Resolution Discrepancy in SSR
Sources
Also known as DEBIAN-CVE-2026-54266, GHSA-39pv-4j6c-2g6v, UBUNTU-CVE-2026-54266.