CVE-2026-111754 Angular CVE debrief

Who should care

Defenders responsible for `@angular/platform-server` deployments should assess exposure and prioritize patching or mitigation to prevent potential open redirect attacks. This includes operators managing affected systems, platform administrators, vulnerability management teams, and security teams responsible for monitoring and incident response. They should review the supplied official advisory or CVE record to validate affected scope, severity, and vendor

Why it matters

CVE-2026-111754 is an open redirect vulnerability in `@angular/platform-server` that requires verification of affected versions and potential exploitation to prevent protocol-relative URL attacks.

• Potential open redirect attacks
• Protocol-relative URL exploitation
• Server-Side Rendering (SSR) vulnerability

Technical summary

The vulnerability is caused by the way `@angular/platform-server` handles protocol-relative URLs in Server-Side Rendering (SSR). When a request URL includes a popping dot-segment followed by multiple slashes, the input bypasses the initial check and results in a `pathname` starting with `//`. This can lead to an HTTP 302 redirect with `Location: //evil.test`, which browsers resolve as a protocol-relative navigation off-origin.

Defensive priority

Defenders should prioritize verifying the affected versions of `@angular/platform-server` and applying patches or mitigations to prevent potential open redirect attacks.

Recommended defensive actions

• Verify the affected versions of `@angular/platform-server` and apply patches or mitigations.
• Monitor for potential open redirect attacks.
• Implement additional security measures to prevent protocol-relative URL attacks.
• Review compensating controls for exposed systems while remediation is scheduled and verified.
• Check relevant monitoring, detection, and logs for exposed assets that need extra review.
• Track exceptions, retest remediated assets, and close the item only after evidence is documented.
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up.

Evidence notes

The vulnerability is caused by the way `@angular/platform-server` handles protocol-relative URLs in Server-Side Rendering (SSR). When a request URL includes a popping dot-segment followed by multiple slashes, the input bypasses the initial check and results in a `pathname` starting with `//`. This can lead to an HTTP 302 redirect with `Location: //evil.test`, which browsers resolve as a protocol-relative navigation off-origin.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.