CVE-2026-29000

pac4j-jwt JwtAuthenticator Authentication Bypass

Published Mar 4, 2026 CVSS 4.0 · 9.3 Critical EPSS 6.2% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-pm7g-w2cf-q238 pac4j-jwt: JwtAuthenticator Authentication Bypass via JWE-Wrapped PlainJWT
History
Type Values Removed Values Added
Metrics cvssV3_1

{'score': 10, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:L'}

cvssV4_0

{'score': 10, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:L/SC:H/SI:H/SA:L'}

cvssV3_1

{'score': 9.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N'}

cvssV4_0

{'score': 9.3, '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'}

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Pac4j
Pac4j pac4j
CPEs cpe:2.3:a:pac4j:pac4j:*:*:*:*:*:*:*:*
Vendors & Products Pac4j
Pac4j pac4j
Type Values Removed Values Added
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.
Title pac4j-jwt JwtAuthenticator Authentication Bypass
Weaknesses CWE-347
References
Metrics cvssV3_1

{'score': 10, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:L'}

cvssV4_0

{'score': 10, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:L/SC:H/SI:H/SA:L'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
VulnCheck
Published
Updated
Oct 8, 2026, 3:22 PM
Reserved
Mar 3, 2026, 4:42 PM
Status
Deferred
Published
Mar 4, 2026, 10:16 PM
Modified
Oct 8, 2026, 4:17 PM