Verbose Logging Exposes Auth & Cookie Headers in Keycloak
CVE-2025-11537 Published on February 10, 2026
Keycloak-server: sensitive headers shown in the http access logs
A flaw was found in Keycloak. When the logging format is configured to a verbose, user-supplied pattern (such as the pre-defined 'long' pattern), sensitive headers including Authorization and Cookie are disclosed to the logs in cleartext. An attacker with read access to the log files can extract these credentials (e.g., bearer tokens, session cookies) and use them to impersonate users, leading to a full account compromise.
Vulnerability Analysis
CVE-2025-11537 can be exploited with local system access, requires user interaction and a small amount of user privileges. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have a high impact on confidentiality, with no impact on integrity and availability.
Timeline
Reported to Red Hat.
Made public.
Weakness Type
Improper Output Neutralization for Logs
The software does not neutralize or incorrectly neutralizes output that is written to logs.
Products Associated with CVE-2025-11537
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Affected Versions
Red Hat Build of Keycloak:Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.