CVE-2026-29000

Summary

pac4j-jwt versions prior to 4.5.9, 5.7.9, and 6.3.3 contain an authentication bypass vulnerability in JwtAuthenticator when processing encrypted JWTs that allows remote attackers to forge authentication tokens. Attackers who possess the server's RSA public key can create a JWE-wrapped PlainJWT with arbitrary subject and role claims, bypassing signature verification to authenticate as any user including administrators.

Affected Software

VendorProductVersion RangeStatus
pac4jpac4j-jwt4.0 < 4.5.9affected
pac4jpac4j-jwt5.0 < 5.7.9affected
pac4jpac4j-jwt6.0 < 6.3.3affected

Weaknesses

  • CWE-347: CWE-347 Improper Verification of Cryptographic Signature

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: poc
    • Automatable: yes
    • Technical Impact: total

References