CVE-2026-55954 Missing ID token claim validation in ueberauth_apple allows account takeover
Attackers can hijack user accounts by replaying unvalidated Apple ID tokens due to missing claim checks in the ueberauth_apple library.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-55954?
CVE-2026-55954 is a critical authentication bypass vulnerability in ueberauth_apple, published on 14 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Weakness: CWE-290
Which versions are affected by CVE-2026-55954?
1 open source package ship an affected version, including ueberauth_apple.
| Package | Affected | Fixed in |
|---|---|---|
ueberauth_apple Hex | From 0.1.0 | 0.6.2 |
How do I fix CVE-2026-55954?
Upgrade ueberauth_apple to 0.6.2 or later.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-55954 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-55954 exists.
Sources
Also known as EEF-CVE-2026-55954, GHSA-pxx8-68pc-p9mr.