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.

Metrics

Attack Vector Network

Attack Complexity Low

Privileges Required Low

Attack Requirements None

User Interaction None

Vulnerable System Confidentiality Impact High

Vulnerable System Integrity Impact High

Vulnerable System Availability Impact None

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

Attack Vector Network

Attack Complexity Low

Privileges Required Low

Scope Unchanged

Confidentiality Impact High

Integrity Impact High

Availability Impact None

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

Affected Vendors & Products

Vendors Products
Pac4j Subscribe
Pac4j Subscribe

No data.

No data.

No data.

Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://github.com/pac4j/pac4j cve-icon
https://github.com/pac4j/pac4j/blob/pac4j-parent-6.5.5/pac4j-oidc/src/main/java/org/pac4j/oidc/authorization/generator/KeycloakRolesAuthorizationGenerator.java cve-icon
https://github.com/pac4j/pac4j/commit/2270c3ff70e93cc43831e75702acd5135531237e cve-icon
https://www.pac4j.org/blog/security-advisory-pac4j-core-oidc-saml.html cve-icon
https://www.vulncheck.com/advisories/pac4j-oidc-before-6.5.6-privilege-escalation-via-unverified-keycloak-access-token cve-icon
History

Sat, 29 Aug 2026 16:45:00 +0000

Type Values Removed Values Added
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.
Title pac4j-oidc before 6.5.6 Privilege Escalation via Unverified Keycloak Access Token
First Time appeared Pac4j
Pac4j pac4j
Weaknesses CWE-347
CPEs cpe:2.3:a:pac4j:pac4j:*:*:*:*:*:*:*:*
Vendors & Products Pac4j
Pac4j pac4j
References
Metrics cvssV3_1

{'score': 8.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N'}

cvssV4_0

{'score': 8.6, 'vector': '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'}

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-08-29T16:35:25.482Z

Reserved: 2026-08-29T14:11:00.266Z

Link: CVE-2026-82461

cve-icon Vulnrichment

No data.

cve-icon NVD

No data.

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses