CVE-2026-82461 pac4j-oidc before 6.5.6 Privilege Escalation via Unverified Keycloak Access Token
Attackers can forge Keycloak access tokens to bypass authorization checks and escalate privileges in applications using pac4j-oidc.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-82461?
CVE-2026-82461 is a high-severity authentication bypass vulnerability in pac4j, published on 29 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
pac4j-oidc before 6.5.6 fails to verify access token signatures, issuers, audiences, or expiry when extracting Keycloak realm and client roles. Attackers can forge access tokens with administrative roles paired with valid ID tokens to bypass authorization checks in applications relying on pac4j role validation.
Weakness: CWE-347
Which versions are affected by CVE-2026-82461?
How do I fix CVE-2026-82461?
No fix has been published for CVE-2026-82461 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-2026-82461 being exploited?
There is no known exploitation of CVE-2026-82461 in the wild and no public exploit code.
Sources
Also known as GHSA-4w24-77rp-687q.