highVulnerability

CVE-2026-88056

### Summary A discrepancy between WHATWG URL parsing and Angular SSR's URL resolution allows attackers to bypass same-origin checks and cause Server-Side Request Forgery (SSRF), potentially leaking sensitive server-side credentials. ### Technical Description When applications validate incoming URLs using the WHATWG URL standard (`new URL(input, trustedOrigin)`), Unicode whitespace characters (such as NO-BREAK SPACE `U+00A0` or ZERO WIDTH NO-BREAK SPACE `U+FEFF`) are not stripped and are evaluated as part of a same-origin relative path (e.g. `http://trusted-origin/%C2%A0//attacker.example/collect`). Consequently, these URLs successfully pass application-level same-origin checks. However, `@angular/platform-server`'s URL resolution utility (`resolveUrl` / `parseUrl`) previously executed `String.prototype.trim()`. Because JavaScript's `String.prototype.trim()` strips all Unicode whitespace (including `U+00A0`), the leading non-breaking space was removed, converting the string into a cross-origin protocol-relative URL (`//attacker.example/collect`). When resolved during server-side rendering (such as in `relativeUrlsTransformerInterceptorFn`), this caused the HTTP request to be dispatched to the attacker-controlled origin (`http://attacker.example/collect`), leaking any credentials (such as `Authorization` headers) attached by the application for the intended same-origin request. ### Impact & Reachability * **Reachability**: The vulnerability affects Angular Server-Side Rendering (SSR) applications where user-controlled input influences resource or request URLs processed by Angular's `HttpClient`, an application-level same-origin check is performed before dispatching, and sensitive server-side credentials (such as API keys or Bearer tokens) are attached to approved requests. * **Impact**: Successful exploitation allows attackers to bypass same-origin validation, triggering Server-Side Request Forgery (SSRF) and leaking sensitive server-side credentials attached to th

Properties

ghsa_id
GHSA-f6mr-pjwc-34m4
summary
Angular: SSRF and Cross-Origin Credential Disclosure via URL Resolution Discrepancy in SSR
severity
high
cve_id
CVE-2026-88056
is_ghsa_only
false
ghsa_published
2026-09-10T20:19:43Z
source_url
https://github.com/advisories/GHSA-f6mr-pjwc-34m4
ghsa_updated
2026-09-10T20:19:44Z

Related Entities (4)

REPORTED_BY (1)

[Source]GitHub Advisory Database

VULNERABLE_TO (1)

[Software]npm/@angular/platform-server

AFFECTS (1)

[Software]npm/@angular/platform-server

HAS_WEAKNESS (1)

[Weakness]Server-Side Request Forgery (SSRF)

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CVE-2026-88056 — Ninja Signal Threat Intelligence | Ninja Signal