CVE-2026-29000
pac4j-jwt JwtAuthenticator Authentication Bypass
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.
INFO
Published Date :
March 4, 2026, 10:16 p.m.
Last Modified :
March 10, 2026, 8:16 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | CRITICAL | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 3.1 | CRITICAL | [email protected] | ||||
| CVSS 3.1 | CRITICAL | MITRE-CVE | ||||
| CVSS 3.1 | CRITICAL | [email protected] | ||||
| CVSS 4.0 | CRITICAL | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 4.0 | CRITICAL | [email protected] | ||||
| CVSS 4.0 | CRITICAL | [email protected] |
Solution
- Update pac4j-jwt to version 4.5.9 or later.
- Update pac4j-jwt to version 5.7.9 or later.
- Update pac4j-jwt to version 6.3.3 or later.
Public PoC/Exploit Available at Github
CVE-2026-29000 has a 16 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-29000.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-29000 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-29000
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Proof-of-Concept (PoC) for an authentication bypass vulnerability affecting applications using pac4j-jwt with JWE (JSON Web Encryption).
authentication-bypass hackthebox cve-2026-29000
Python
Python Proof of Concept (PoC) for CVE-2026-29000: pac4j-jwt Authentication Bypass via Public Key JWE Forgery.
Python
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Shell
#Writeup #Principal #HTB
cve-2026-29000 exploit
Python Shell
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Python
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Python
CVE-2026-29000 - pac4j-jwt Authentication Bypass PoC
Python
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Dockerfile Java
pac4j-jwt JwtAuthenticator auth bypass (CVE-2026-29000) writeup and PoCs
Java Python Dockerfile
Latest CVEs with their Proof of Concept exploits.
Python HTML
TOP All bugbounty pentesting CVE-2023- POC Exp RCE example payload Things
bugbounty cve exp exploit payload poc rce vulnerability
Shell
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-29000 vulnerability anywhere in the article.
-
Daily CyberSecurity
Critical 10.0 CVSS Flaw in pac4j-jwt Lets Hackers Forge Admin Tokens
Cybersecurity researchers have uncovered a critical vulnerability in pac4j-jwt, a popular Java-based library used to secure thousands of applications through JSON Web Tokens (JWT). The flaw, tracked a ... Read more
The following table lists the changes that have been made to the
CVE-2026-29000 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by [email protected]
Mar. 10, 2026
Action Type Old Value New Value Added CVSS V4.0 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 Removed CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:L/SC:H/SI:H/SA:L/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 Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N Removed CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:L -
New CVE Received by [email protected]
Mar. 04, 2026
Action Type Old Value New Value 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. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:L/SC:H/SI:H/SA:L/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 Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:L Added CWE CWE-347 Added Reference https://www.codeant.ai/security-research/pac4j-jwt-authentication-bypass-public-key Added Reference https://www.pac4j.org/blog/security-advisory-pac4j-jwt-jwtauthenticator.html Added Reference https://www.vulncheck.com/advisories/pac4j-jwt-jwtauthenticator-authentication-bypass