CVE-2026-29000pac4j-jwt JwtAuthenticator Authentication Bypass
Updated under an hour ago ()
Does this affect you?
It affects pac4j-jwt. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
Do this next
Free account, 1 product
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.
- CVSS
- 9.1 CRITICAL (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
- Weakness (CWE)
- CWE-347
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- VulnCheck
- NVD analysis
- Deferred
- Record last updated
- Oct 8, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
pac4j pac4j-jwt pac4j:jwt (from the name) | from 4.0 before 4.5.9; from 5.0 before 5.7.9; from 6.0 before 6.3.3 | CNA record |
References
- https://www.pac4j.org/blog/security-advisory-pac4j-jwt-jwtauthenticator.htmlvendor-advisory
- https://www.codeant.ai/security-research/pac4j-jwt-authentication-bypass-public-keytechnical-description, exploit
- https://www.vulncheck.com/advisories/pac4j-jwt-jwtauthenticator-authentication-bypassthird-party-advisory
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.