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Fencer Vulns
high 7.5

CVE-2026-107602 json

Keycloak-services: keycloak-services: unauthenticated cpu exhaustion via saml 1.1 keyinfo infinite loop

published 2026-11-05 3 d ago modified 2026-11-06 2 d ago also EUVD-2026-117565

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.7%
EPSS 0.7% chance of exploitation in 30 days, percentile 54%
public exploits
0
none known

Summary

A flaw was found in the SAML 1.1 XML parsing logic of Keycloak, an open-source identity and access management solution. The issue occurs when the parser encounters unexpected elements within a security token's key information section, causing the processing thread to enter an infinite loop. An unauthenticated remote attacker could exploit this by sending specially crafted requests, leading to 100% CPU usage and a total denial of service that requires a server restart to resolve.

Patch / fix

  • Red Hat Red Hat build of Keycloak 26.4 26.4-29, 26.4-30, 26.4.17-2
  • Red Hat Red Hat build of Keycloak 26.6 26.6-24, 26.6.8-2

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-2026-107602 updated cvss 7.5

keycloak-services: keycloak-services: Unauthenticated CPU exhaustion via SAML 1.1 KeyInfo infinite loop

  • Red Hat build of Keycloak 26.4 rhbk/keycloak-rhel9 26.4-29, rhbk/keycloak-rhel9-operator 26.4-30, rhbk/keycloak-operator-bundle 26.4.17-2
    fixed: vendor fix RHSA-2026:95760
  • Red Hat build of Keycloak 26.4.17
    fixed: vendor fix RHSA-2026:95759
  • Red Hat build of Keycloak 26.6 rhbk/keycloak-rhel9 26.6-24, rhbk/keycloak-rhel9-operator 26.6-24, rhbk/keycloak-operator-bundle 26.6.8-2
    fixed: vendor fix RHSA-2026:95762
  • Red Hat build of Keycloak 26.6.8
    fixed: vendor fix RHSA-2026:95761
  • Red Hat Single Sign-On 7 keycloak-services 18.0.19.redhat-00002
    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

Exploit prediction

0.73% chance of exploitation in the next 30 days, higher than 54% 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 26.4.17
  • Red Hat Red Hat build of Keycloak 26.6
  • Red Hat Red Hat build of Keycloak 26.6.8
  • Red Hat Red Hat Single Sign-On 7

Classification

Weakness
  • CWE-835 Loop with Unreachable Exit Condition

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.