CVE-2026-82461: high-severity vulnerability in pac4j
pac4j-oidc before 6.5.6 Privilege Escalation via Unverified Keycloak Access Token
Published · Updated
21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 8.6epss 0.3%
exploitation probability
0.3%top 76% of all CVEs
observed exploitation
nono source reports it
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.
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
Affected products
pac4j · pac4jRelated CVEs — pac4j
In the same product, most dangerous first.
CVE-2023-25581CRITICALDeserialization of untrusted data in InternalAttributeHandler in pac4jEPSS 1.9%CVE-2026-82463HIGHpac4j-core before 6.5.6 Authorization Bypass via Reversed Profile Type CheckEPSS 0.6%CVE-2026-82464MEDIUMpac4j-core before 6.5.6 Open Redirect via Backslash LogoutEPSS 0.3%CVE-2026-82465MEDIUMpac4j-saml before 6.5.6 Session Destruction via Unsigned LogoutRequestEPSS 0.3%CVE-2026-82462MEDIUMpac4j-oidc before 6.5.6 Authentication Bypass via Access Token SubstitutionEPSS 0.2%
References
https://github.com/pac4j/pac4jhttps://github.com/pac4j/pac4j/blob/pac4j-parent-6.5.5/pac4j-oidc/src/main/java/org/pac4j/oidc/authorization/generator/KeycloakRolesAuthorizationGenerator.javahttps://github.com/pac4j/pac4j/commit/2270c3ff70e93cc43831e75702acd5135531237ehttps://www.pac4j.org/blog/security-advisory-pac4j-core-oidc-saml.htmlhttps://www.vulncheck.com/advisories/pac4j-oidc-before-6.5.6-privilege-escalation-via-unverified-keycloak-access-token