CVE-2026-54266
Fix: angular/angular@5f36274CVE-2026-54266 is a CWE-328 vulnerability in @angular/common. O3 Security confirms whether CVE-2026-54266 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Angular: Weak 32-Bit Cache Key Hashing in `HttpTransferCache` Leading to Cross-Request Data Leakage and State Poisoning
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-54266.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
@angular/commonnpmDescription
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @angular/common | ≥ 22.0.0-next.0&&< 22.0.1 | 22.0.1 |
| 📦npm | @angular/common | ≥ 21.0.0-next.0&&< 21.2.17 | 21.2.17 |
| 📦npm | @angular/common | ≥ 20.0.0-next.0&&< 20.3.25 | 20.3.25 |
| 📦npm | @angular/common | all versions | No fix |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @angular/common. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update @angular/common to 22.0.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-54266 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-54266 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-54266. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-54266 in your dependencies?
O3 detects CVE-2026-54266 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.