CVE-2026-55954
What it is
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.
At a glance
- Exploitability
- Can be exploited over the network without logging in. High risk of data exposure, data tampering.
- Exploit odds
- 0.5% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.5% in the next 30 days (EPSS).
- Severity: 9.1 CRITICAL (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.5% · EPSS, next 30 days
- Weakness
- CWE-290
- Record status
- Deferred
Attack profile CVSS 4.0 · 9.1
- Attack vector
- Network
- Complexity
- Low
- Attack requirements
- Present
- Privileges needed
- None
- User interaction
- None
- Confidentiality
- High
- Integrity
- High
- Availability
- None
Raw vector
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-55954.md and follow it. Check whether this project is affected by CVE-2026-55954. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://github.com/ueberauth/ueberauth_apple/commit/01e2d9c9b3134e1b78633ad82d136d5ff4a61f28
- https://github.com/ueberauth/ueberauth_apple/security/advisories/GHSA-pxx8-68pc-p9mr
- https://github.com/ueberauth/ueberauth_apple/security/advisories/GHSA-pxx8-68pc-p9mr
References
- https://cna.erlef.org/cves/CVE-2026-55954.html
- https://github.com/ueberauth/ueberauth_apple/commit/01e2d9c9b3134e1b78633ad82d136d5ff4a61f28
- https://github.com/ueberauth/ueberauth_apple/security/advisories/GHSA-pxx8-68pc-p9mr
- https://osv.dev/vulnerability/EEF-CVE-2026-55954
- https://github.com/ueberauth/ueberauth_apple/security/advisories/GHSA-pxx8-68pc-p9mr