CVE-2026-82462 pac4j-oidc before 6.5.6 Authentication Bypass via Access Token Substitution
Attackers can bypass authentication in pac4j-oidc by substituting access tokens, creating unauthorized sessions without proper validation.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-82462?
CVE-2026-82462 is a medium-severity authentication bypass vulnerability in pac4j, published on 29 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
pac4j-oidc before 6.5.6 accepts OIDC callbacks carrying only an access token without authorization code or ID token validation. Attackers can substitute access tokens minted for other clients to create authenticated sessions without proper issuer, audience, nonce, or subject verification.
Weakness: CWE-345
Which versions are affected by CVE-2026-82462?
How do I fix CVE-2026-82462?
No fix has been published for CVE-2026-82462 yet. Limit exposure of the affected software until one is available.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-82462 being exploited?
There is no known exploitation of CVE-2026-82462 in the wild and no public exploit code.
Sources
Also known as GHSA-w9jq-4xjw-37gj.