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TI-2026-02198 Aliases CVE-2026-2575GHSA-xv6h-r36f-3gp5

Keycloak: keycloak: denial of service due to excessive samlrequest decompression

Priority LOW 31CWE-409Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
None · None · Low
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA, GitHub and Red Hat.

Summary

A flaw was found in Keycloak. An unauthenticated remote attacker can trigger an application level Denial of Service (DoS) by sending a highly compressed SAMLRequest through the SAML Redirect Binding. The server fails to enforce size limits during DEFLATE decompression, leading to an OutOfMemoryError (OOM) and subsequent process termination. This vulnerability allows an attacker to disrupt the availability of the service.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00663 51st percentileScored 2026-11-07
Fix Fixed org.keycloak:keycloak-saml-adapter-core (Maven): 26.5.4org.keycloak:keycloak-saml-core (Maven): 26.5.4+1 more productRed Hat: 7 advisories

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
Red HatRed Hat build of Keycloak 26.4—26.4.10-1Patch availableCNA
Red HatRed Hat build of Keycloak 26.4—26.4-12Patch availableCNA
Red HatRed Hat build of Keycloak 26.4—26.4-12Patch availableCNA
Red HatRed Hat build of Keycloak 26.4.10——Not affectedCNA
Red HatRed Hat Single Sign-On 7.6.13——Not affectedCNA
Red HatRed Hat Single Sign-On 7.6 for RHEL 7—18.0.20-1.redhat_00001.1.el7ssoPatch availableCNA
Red HatRed Hat Single Sign-On 7.6 for RHEL 8—18.0.20-1.redhat_00001.1.el8ssoPatch availableCNA
Red HatRed Hat Single Sign-On 7.6 for RHEL 9—18.0.20-1.redhat_00001.1.el9ssoPatch availableCNA
Red HatRHEL-8 based Middleware Containers—7.6-85Patch availableCNA
—org.keycloak:keycloak-saml-adapter-core (Maven)before 26.5.426.5.4Patch availableGHSA-xv6h-r36f-3gp5
—org.keycloak:keycloak-saml-core (Maven)before 26.5.426.5.4Patch availableGHSA-xv6h-r36f-3gp5
—org.keycloak:keycloak-services (Maven)before 26.5.426.5.4Patch availableGHSA-xv6h-r36f-3gp5
  • Red Hat build of Keycloak 26.4 VendorRed Hat Affected — Fixed in 26.4.10-1 Patch available CNA
  • Red Hat build of Keycloak 26.4 VendorRed Hat Affected — Fixed in 26.4-12 Patch available CNA
  • Red Hat build of Keycloak 26.4 VendorRed Hat Affected — Fixed in 26.4-12 Patch available CNA
  • Red Hat build of Keycloak 26.4.10 VendorRed Hat Affected — Fixed in — Not affected CNA
  • Red Hat Single Sign-On 7.6.13 VendorRed Hat Affected — Fixed in — Not affected CNA
  • Red Hat Single Sign-On 7.6 for RHEL 7 VendorRed Hat Affected — Fixed in 18.0.20-1.redhat_00001.1.el7sso Patch available CNA
  • Red Hat Single Sign-On 7.6 for RHEL 8 VendorRed Hat Affected — Fixed in 18.0.20-1.redhat_00001.1.el8sso Patch available CNA
  • Red Hat Single Sign-On 7.6 for RHEL 9 VendorRed Hat Affected — Fixed in 18.0.20-1.redhat_00001.1.el9sso Patch available CNA
  • RHEL-8 based Middleware Containers VendorRed Hat Affected — Fixed in 7.6-85 Patch available CNA
  • org.keycloak:keycloak-saml-adapter-core (Maven) Vendor— Affected before 26.5.4 Fixed in 26.5.4 Patch available GHSA-xv6h-r36f-3gp5
  • org.keycloak:keycloak-saml-core (Maven) Vendor— Affected before 26.5.4 Fixed in 26.5.4 Patch available GHSA-xv6h-r36f-3gp5
  • org.keycloak:keycloak-services (Maven) Vendor— Affected before 26.5.4 Fixed in 26.5.4 Patch available GHSA-xv6h-r36f-3gp5

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:redhat:build_of_keycloak:*:*:*:*:*:*:*:*26.4 to before 26.4.10VulnerableRed Hat
  • cpe:2.3:a:redhat:build_of_keycloak:*:*:*:*:*:*:*:* Versions 26.4 to before 26.4.10 Vulnerable ·Red Hat

Remediation

  • Fix · GHSA-xv6h-r36f-3gp5 org.keycloak:keycloak-saml-adapter-core (Maven) Fixed in 26.5.4 Advisory →
  • Fix · GHSA-xv6h-r36f-3gp5 org.keycloak:keycloak-saml-core (Maven) Fixed in 26.5.4 Advisory →
  • Fix · GHSA-xv6h-r36f-3gp5 org.keycloak:keycloak-services (Maven) Fixed in 26.5.4 Advisory →

Red Hat 7 advisories

  • RHSA-2026:76128 Released 2026-10-06 · Red Hat rating Important
    Red Hat Single Sign-On 7.6.13 security update on RHEL 7
    • Red Hat Single Sign-On 7.6 for RHEL 7 Server rh-sso7-keycloak-18.0.20-1.redhat_00001.1.el7sso, rh-sso7-keycloak-server-18.0.20-1.redhat_00001.1.el7sso
  • RHSA-2026:76130 Released 2026-10-06 · Red Hat rating Important
    Red Hat Single Sign-On 7.6.13 security update on RHEL 9
    • Red Hat Single Sign-On 7.6 for RHEL 9 rh-sso7-keycloak-18.0.20-1.redhat_00001.1.el9sso, rh-sso7-keycloak-server-18.0.20-1.redhat_00001.1.el9sso
  • RHSA-2026:76129 Released 2026-10-06 · Red Hat rating Important
    Red Hat Single Sign-On 7.6.13 security update on RHEL 8
    • Red Hat Single Sign-On 7.6 for RHEL 8 rh-sso7-keycloak-18.0.20-1.redhat_00001.1.el8sso, rh-sso7-keycloak-server-18.0.20-1.redhat_00001.1.el8sso
Show 4 more Red Hat advisories
  • RHSA-2026:76134 Released 2026-10-05 · Red Hat rating Important
    Red Hat Single Sign-On 7.6.13 for OpenShift image security update
    • Middleware Containers for OpenShift rh-sso-7/sso76-openshift-rhel8
  • RHSA-2026:76132 Released 2026-10-05 · Red Hat rating Important
    Red Hat Single Sign-On 7.6.13 security update
    • Red Hat Single Sign-On 7.6.13
  • RHSA-2026:3948 Released 2026-03-05 · Red Hat rating Important
    Red Hat build of Keycloak 26.4.10 Images Update
    • Red Hat build of Keycloak 26.4 rhbk/keycloak-operator-bundle, rhbk/keycloak-rhel9, rhbk/keycloak-rhel9-operator
  • RHSA-2026:3947 Released 2026-03-05 · Red Hat rating Important
    Red Hat build of Keycloak 26.4.10 Update
    • Red Hat build of Keycloak 26.4.10

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Middleware Containers for OpenShiftFixed RHSA-2026:76134
Red Hat Single Sign-On 7.6 for RHEL 7 ServerFixed RHSA-2026:76128
Red Hat Single Sign-On 7.6 for RHEL 8Fixed RHSA-2026:76129
Red Hat Single Sign-On 7.6 for RHEL 9Fixed RHSA-2026:76130
Red Hat Single Sign-On 7.6.13Fixed RHSA-2026:76132
Red Hat build of Keycloak 26.4Fixed RHSA-2026:3948
Red Hat build of Keycloak 26.4.10Fixed RHSA-2026:3947

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-2575
  2. 2026-10-03 Alias added: GHSA-xv6h-r36f-3gp5
  3. 2026-10-06 EPSS moved to the 50th–90th percentile
  4. 2026-10-06 Fix available: rh-sso-7/[email protected] · CNA
  5. 2026-10-06 2 new references · CNA
  6. 2026-10-06 2 new references · GHSA-xv6h-r36f-3gp5
  7. 2026-10-06 Fix available: RHSA-2026:76134 · Red Hat
  8. 2026-10-06 Fix available: RHSA-2026:76132 · Red Hat
  9. 2026-10-06 Fix available: RHSA-2026:76129 · Red Hat
  10. 2026-10-06 Fix available: RHSA-2026:76130 · Red Hat
  11. 2026-10-06 Fix available: Middleware Containers for OpenShift, Red Hat Single Sign-On 7.6 for RHEL 8, Red Hat Single Sign-On 7.6 for RHEL 9 +1 · Red Hat
  12. 2026-10-06 Fix available: rh-sso7-keycloak@0:18.0.20-1.redhat_00001.1.el8sso, rh-sso7-keycloak@0:18.0.20-1.redhat_00001.1.el9sso · CNA
  13. 2026-10-06 2 new references · CNA
  14. 2026-10-06 2 new references · GHSA-xv6h-r36f-3gp5
  15. 2026-10-06 Fix available: rh-sso7-keycloak@0:18.0.20-1.redhat_00001.1.el7sso · CNA
  16. 2026-10-06 1 new reference · CNA
  17. 2026-10-06 1 new reference · GHSA-xv6h-r36f-3gp5
  18. 2026-10-07 Fix available: RHSA-2026:76128 · Red Hat
  19. 2026-10-07 Fix available: Red Hat Single Sign-On 7.6 for RHEL 7 Server · Red Hat

References

Advisory 10

Other 3

  • TI-2026-02223 Keycloak: keycloak: unauthorized authentication via disabled saml identity provider CVSS 3.1HIGH 8.1
  • TI-2024-01049 Keycloak: path transversal in redirection validation CVSS 3.1HIGH 8.1
  • TI-2026-13740 Keycloak-services: keycloak-services: saml idp-initiated broker login bypasses link-only restriction CVSS 3.1CRITICAL 9.8
  • TI-2026-13741 Keycloak-services: keycloak-services: saml broker metadata import disables response signature validation CVSS 3.1CRITICAL 9.1
  • TI-2026-13106 Keycloak-services: keycloak-services: dcr protocol mapper type-swap policy bypass allows privilege escalation CVSS 3.1HIGH 8.8
  • TI-2026-02631 Authentication bypass in Red Hat build of Keycloak 26.2 CVSS 3.1HIGH 8.8
See all 110 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences