CVE-2026-29000

critical · 9.3

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.

9.3

CVSS

5.9%

EPSS (exploit prob.)

93rd

EPSS percentile

2026-03-04

Published

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/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

Weaknesses

CWE-347

References

https://www.codeant.ai/security-research/pac4j-jwt-authentication-bypass-public-key
https://www.pac4j.org/blog/security-advisory-pac4j-jwt-jwtauthenticator.html
https://www.vulncheck.com/advisories/pac4j-jwt-jwtauthenticator-authentication-bypass

Query this programmatically:

curl https://evil-db.io/api/v1/cve/CVE-2026-29000