CVE-2026-55954
Missing ID token claim validation in ueberauth_apple allows account takeover
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.
Detection & mitigation playbook
VulnerabilityDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for the affected component. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Remediation status
No patched version of the affected component has shipped for CVE-2026-55954 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-55954 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-55954. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-55954 in your dependencies?
O3 detects CVE-2026-55954 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.