CVE-2026-53776 PUBLISHED

Perry < 0.5.1166 JWT Expiration Bypass via verify_decode

Assigner: VulnCheck
Reserved: 10.06.2026 Published: 16.06.2026 Updated: 16.06.2026

Perry before 0.5.1166 contains a JWT validation vulnerability that allows remote attackers to bypass token expiration by exploiting the unconditional setting of validate_exp = false in the verify_decode helper within the stdlib JWT verification path. Attackers in possession of a previously issued bearer token can present expired tokens to any jwt.verify() call and retain authenticated access indefinitely, bypassing force-expired sessions such as user logout or administrative revocation.

Metrics

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
CVSS Score: 9.3

Product Status

Vendor PerryTS
Product perry
Versions Default: affected
  • affected from 0 to 0.5.1166 (excl.)

Credits

  • Katriel Moses finder
  • VulnCheck finder

References

Problem Types

  • Insufficient Session Expiration CWE