CVE-2026-41423
CVE-2026-41423 is a Server-Side Request Forgery (SSRF) vulnerability in @angular/platform-server. O3 Security confirms whether CVE-2026-41423 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Angular: SSRF via protocol-relative and backslash URLs in Angular Platform-Server
Blast Radius
Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.
@angular/platform-servernpmDescription
Angular is a development platform for building mobile and desktop web applications using TypeScript/JavaScript and other languages. Prior to versions 19.2.21, 20.3.19, 21.2.9, and 22.0.0-next.8, a Server-Side Request Forgery (SSRF) vulnerability exists in @angular/platform-server due to improper handling of URLs during Server-Side Rendering (SSR). When an attacker sends a request such as GET /\evil.com/ HTTP/1.1 the server engine (Express, etc.) passes the URL string to Angular’s rendering functions. Because the URL parser normalizes the backslash to a forward slash for HTTP/HTTPS schemes, the internal state of the application is hijacked to believe the current origin is evil.com. This misinterpretation tricks the application into treating the attacker’s domain as the local origin. Consequently, any relative HttpClient requests or PlatformLocation.hostname references are redirected to the attacker controlled server, potentially exposing internal APIs or metadata services. This issue has been patched in versions 19.2.21, 20.3.19, 21.2.9, and 22.0.0-next.8.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @angular/platform-server | ≥ 22.0.0-next.0&&< 22.0.0-next.8 | 22.0.0-next.8 |
| 📦npm | @angular/platform-server | ≥ 21.0.0-next.0&&< 21.2.9 | 21.2.9 |
| 📦npm | @angular/platform-server | ≥ 20.0.0-next.0&&< 20.3.19 | 20.3.19 |
| 📦npm | @angular/platform-server | ≥ 19.0.0-next.0&&< 19.2.21 | 19.2.21 |
| 📦npm | @angular/platform-server | 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/platform-server. 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/platform-server to 22.0.0-next.8 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-41423 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-2026-41423 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-2026-41423. 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-2026-41423 in your dependencies?
O3 detects CVE-2026-41423 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.