Vulnerability Description
Authentication Bypass by Spoofing vulnerability in ueberauth ueberauth_apple allows account takeover via unvalidated ID token claims. The Ueberauth.Strategy.Apple.Token.payload/2 function verifies the JWT signature of the callback id_token against Apple's JWKS but does not validate any registered claims. The iss, aud, exp, and iat claims are read from the token and passed on to Ueberauth.Strategy.Apple.handle_callback!/1, which derives the logged-in user's uid and email directly from the unvalidated sub claim. An attacker who obtains any Apple-signed ID token bearing the victim's sub (via a captured expired token, or via an ID token issued to a sibling client in the same Apple developer team) can replay it against the vulnerable callback and be authenticated as the victim. The absent exp check makes stolen tokens usable indefinitely, and the absent aud check enables cross-application account takeover across clients that share an Apple developer team. This issue affects ueberauth_apple: from 0.1.0 before 0.6.2.
Related Weaknesses (CWE)
References
- https://cna.erlef.org/cves/CVE-2026-55954.html
- https://github.com/ueberauth/ueberauth_apple/commit/01e2d9c9b3134e1b78633ad82d13
- https://github.com/ueberauth/ueberauth_apple/security/advisories/GHSA-pxx8-68pc-
- https://osv.dev/vulnerability/EEF-CVE-2026-55954
- https://github.com/ueberauth/ueberauth_apple/security/advisories/GHSA-pxx8-68pc-
FAQ
What is CVE-2026-55954?
CVE-2026-55954 is a documented vulnerability. Authentication Bypass by Spoofing vulnerability in ueberauth ueberauth_apple allows account takeover via unvalidated ID token claims. The Ueberauth.Strategy.Apple.Token.payload/2 function verifies th...
How severe is CVE-2026-55954?
CVSS scoring is not yet available for CVE-2026-55954. Check NVD for updates.
Is there a patch for CVE-2026-55954?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.