cvedb.io
CVE-2026-55735
UNKNOWN · CVSS n/a
EPSS exploitation probability: 0%
Published 2026-08-01T19:16:42.510 · Last modified 2026-08-01T19:16:42.510

Summary

Improper Verification of Cryptographic Signature in ueberauth guardian allows an unauthenticated attacker to revoke a victim's session with a forged token. Guardian.revoke/3 in lib/guardian.ex decodes the supplied token with peek/1, which performs no signature verification (it only base64-decodes the JWT header and payload). The resulting unverified claims are forwarded directly to the configured token module's revoke callback and the implementation's on_revoke callback, a state-mutating sink. The sibling operations refresh/2 and exchange/4 both call decode_and_verify first, so the signature is checked before anything acts on the claims; revoke/3 is the only state-mutating path that acts on claims without verifying the signature. An attacker who knows or guesses a victim's identifying cl

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.