CVE-2026-29000
Critical
Description
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.
SeverityCritical
CVSS9.1
Exploit probability—
ProductOrg.pac4j:pac4j-jwt
PublishedMar 4, 2026
First seenMar 4, 2026
Weakness typeCWE-347CWE-347
How to fix
Update
- org.pac4j:pac4j-jwt6.3.3, 5.7.9, 4.5.9 or later
Vendor advisories
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| org.pac4j:pac4j-jwtMaven | 6.0.4.1 ≤ v < 6.3.3, 5.0.0-RC1 ≤ v < 5.7.9, v < 4.5.9 | 6.3.3, 5.7.9, 4.5.9 |
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