CVE-2026-55954
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedAuthentication 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.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceThe ueberauth_apple library verifies JWT signatures on Apple's ID tokens but fails to validate critical claims (iss, aud, exp, iat). The Token.payload/2 function passes unvalidated claims to handle_callback!/1, which derives the user identity directly from the unverified sub claim. This allows attackers to replay stolen or cross-application tokens indefinitely since expiration is never checked.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- Authentication
- X
- User interaction
- None
- Scope
- X
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
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Locate ueberauth_apple in project dependenciesSearch for ueberauth_apple in mix.exs, mix.lock, or your package manager files (e.g., Hex.pm deps file).Affected if ueberauth_apple is listed as a dependency in the project.
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Determine installed version of ueberauth_appleCheck mix.lock for the exact version, or run 'mix hex.info ueberauth_apple' or 'mix deps | grep apple'. Compare the version to 0.6.2.Affected if The installed version is below 0.6.2 (e.g., 0.6.1, 0.6.0, 0.5.x, etc.).
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Verify Apple strategy is configured in ueberauthLook for Uberauth.Strategy.Apple configuration in config/config.exs or runtime config files, typically under config :ueberauth, :ueberauth, providers: [apple: {Uberauth.Strategy.Apple, [...]}]Affected if Apple is configured as an OAuth provider in the ueberauth setup.
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Inspect token handling code for unvalidated claim usageSearch for implementations of handle_callback!/1 or calls to Token.payload/2 in your codebase. Look for direct usage of claims like sub, iss, aud, exp, or iat without prior validation checks.Affected if The application processes Apple ID tokens and accesses claims (especially sub) without explicit validation of iss, aud, exp, or iat.
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Check for custom token validation logicReview any custom plug, controller, or middleware that handles the Apple OAuth callback and inspects the token claims. Look for validation functions that claim to validate tokens.Affected if Custom code handles the callback but does not validate iss (should be https://appleid.apple.com), aud (should be client_id), exp, or iat before trusting the sub claim.
You are affected if ueberauth_apple version below 0.6.2 is installed AND your application uses Apple OAuth for authentication, since the library does not validate essential JWT claims before trusting the token identity.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scopedUpgrade to ueberauth_apple version 0.6.2 or later which implements proper validation of iss, aud, exp, and iat claims before trusting the token for authentication.
0.6.2
- 1. Identify the current version of ueberauth_apple in your project by checking your mix.exs or mix.lock file
- 2. Update the ueberauth_apple dependency in mix.exs to version 0.6.2 or later
- 3. Run mix deps.update ueberauth_apple to fetch the updated package
- 4. Run mix deps.compile to compile the updated dependencies
- 5. Test the Apple OAuth login flow to verify the fix works correctly
- 6. Deploy the updated application
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation3.0 h
- Testing3.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-55954 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-55954 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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