CVE-2026-18208

Public on 2026-07-31
Modified on 2026-07-31
Description
A flaw was found in the OIDC token introspection endpoint of the keycloak-services component. Keycloak is an open-source identity and access management solution used to secure modern applications and services. The issue occurs when a confidential client, configured to receive signed JWT introspection responses, attempts to introspect a token issued for a different audience. Although the endpoint correctly identifies the token as inactive for that client, it still returns the full set of token claims within a signed JWT field. This allows an unauthorized client to bypass audience-based restrictions and access sensitive information contained in the token.
Severity
Medium severity
Medium
See what this means
CVSS v3 Base Score
6.5
See breakdown

Affected Packages

Platform Package Release Date Advisory Status
Amazon Linux 2 - Core keycloak-httpd-client-install Not Affected

CVSS Scores

Score Type Score Vector
Amazon Linux CVSSv3 6.5 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N