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Fencer Vulns
high 7.5

CVE-2026-79651 json

Keycloak-services: keycloak-services: unauthenticated dos via unbounded locale caching

published 2026-09-16 53 d ago modified 2026-09-25 45 d ago also EUVD-2026-80830

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.8%
EPSS 0.8% chance of exploitation in 30 days, percentile 57%
public exploits
0
none known

Summary

A flaw was found in the theme localization endpoints of the keycloak-services component, which is the core service responsible for authentication flows and theme management in Keycloak. The issue occurs because the system accepts arbitrary locale tags from unauthenticated requests and stores them in a permanent in-memory cache without limits. An attacker can exploit this by sending a large number of unique locale tags, eventually causing the server to run out of memory and crash.

Patch / fix

  • Red Hat Red Hat build of Keycloak 26.4 26.4-26, 26.4.16-2
  • Red Hat Red Hat build of Keycloak 26.6 26.6-20, 26.6.7-3

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-2026-79651 updated cvss 7.5

keycloak-services: keycloak-services: unauthenticated DoS via unbounded locale caching

  • Red Hat build of Keycloak 26.4 rhbk/keycloak-rhel9 26.4-26, rhbk/keycloak-rhel9-operator 26.4-26, rhbk/keycloak-operator-bundle 26.4.16-2
    fixed: vendor fix RHSA-2026:68276
  • Red Hat build of Keycloak 26.4.16
    fixed: vendor fix RHSA-2026:68280
  • Red Hat build of Keycloak 26.6 rhbk/keycloak-rhel9 26.6-20, rhbk/keycloak-rhel9-operator 26.6-20, rhbk/keycloak-operator-bundle 26.6.7-3
    fixed: vendor fix RHSA-2026:68277
  • Red Hat build of Keycloak 26.6.7
    fixed: vendor fix RHSA-2026:68278
  • Red Hat Single Sign-On 7 keycloak-services 18.0.3.redhat-00001
    not affected: vulnerable code not present

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
yes
Technical impact
partial
Assessed
53 d ago

Exploit prediction

0.81% chance of exploitation in the next 30 days, higher than 57% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

  • Red Hat Red Hat build of Keycloak 26.4
  • Red Hat Red Hat build of Keycloak 26.4.16
  • Red Hat Red Hat build of Keycloak 26.6
  • Red Hat Red Hat build of Keycloak 26.6.7
  • Red Hat Red Hat Single Sign-On 7

Classification

Weakness
  • CWE-400 Uncontrolled Resource Consumption

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.