CVE-2026-103884

A flaw was found in the X.509 client certificate authenticator of Keycloak. When CRL Distribution Point checking is enabled, the server fails to properly validate the file paths provided in a client certificate. An attacker can provide a specially crafted certificate that causes the server to attempt to read sensitive files from the local system or exhaust memory by loading extremely large files, potentially leading to information disclosure or a system crash.

  • Published Oct 1, 2026
  • CVSS 6.5 medium
  • 0.2% chance of exploitation in the next 30 days (EPSS)

Affected software

CVE-2026-103884 at the National Vulnerability Database