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Fencer Vulns
medium 5.0

CVE-2025-11537 json

Keycloak-services: sensitive headers shown in the http access logs

published 2026-02-10 8 mo ago modified 2026-10-30 9 d ago also GHSA-gv3v-2cpp-3pmq , EUVD-2025-207355

cvss
5.0
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 6%
public exploits
0
none known

Summary

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.

Patch / fix

  • maven org.keycloak:keycloak-quarkus-server 26.5.6

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2025-11537 updated cvss 5.0

keycloak-services: Sensitive headers shown in the HTTP access logs

  • Red Hat Build of Keycloak rhbk/keycloak-rhel9
    affected: workaround, no fix available
  • Red Hat build of Keycloak 26.4.2
    fixed: vendor fix RHEA-2025:19386

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
8 mo ago

Exploit prediction

0.17% chance of exploitation in the next 30 days, higher than 6% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 5.0 CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N
GitHub 3.1 5.0 CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N

Affected packages

ecosystem package affected fixed in
maven org.keycloak:keycloak-quarkus-server
<26.5.6
26.5.6

Affected products

  • Red Hat Red Hat build of Keycloak 26.4.2
  • Red Hat Red Hat Build of Keycloak

Classification

Weakness
  • CWE-117 Improper Output Neutralization for Logs

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.