ueberauth_apple: Authentication Bypass by Spoofing
CVE-2026-55954 is a critical-severity authentication bypass by spoofing vulnerability in ueberauth_apple from Ueberauth, with a CVSS 4.0 base score of 9.1 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 0.6.2, 01e2d9c9b3134e1b78633ad82d136d5ff4a61f28 as the first without the flaw, so updating ueberauth_apple to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.51% chance of exploitation within 30 days, which is low compared with other CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Update ueberauth_apple to 0.6.2 or 01e2d9c9b3134e1b78633ad82d136d5ff4a61f28, whichever matches your release line, or a later version.
- Read the advisory on github.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Ueberauth | ueberauth_apple | 0.1.0 up to, but not including, 0.6.2; 3908a187d045c75994b62ce340c3aa26bb8976b8 up to, but not including, 01e2d9c9b3134e1b78633ad82d136d5ff4a61f28 | 0.6.2, 01e2d9c9b3134e1b78633ad82d136d5ff4a61f28 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Attack requirements
- PresentThe target must be in a specific state or configuration for the attack to work.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Confidentiality (vulnerable system)
- HighSerious loss of confidentiality on the vulnerable system.
- Integrity (vulnerable system)
- HighSerious loss of integrity on the vulnerable system.
- Availability (vulnerable system)
- NoneNo loss of availability on the vulnerable system.
- Confidentiality (other systems)
- NoneNo loss of confidentiality on systems beyond the vulnerable one.
- Integrity (other systems)
- NoneNo loss of integrity on systems beyond the vulnerable one.
- Availability (other systems)
- NoneNo loss of availability on systems beyond the vulnerable one.
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. Scored by CNA.
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.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Authentication Bypass by Spoofing
This attack-focused weakness is caused by incorrectly implemented authentication schemes that are subject to spoofing attacks.
More Authentication Bypass by Spoofing vulnerabilities (CWE-290)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Recent Authentication Bypass by Spoofing vulnerabilities
- 7.5 High severity
- 9.1 Critical severity
- 8.1 High severity
- 9.8 Critical severity
- 7.3 High severity
- 8.2 High severity
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