Keycloak: keycloak: denial of service due to excessive samlrequest decompression (Red Hat Red Hat build of Keycloak 26.4)
At a glance
- Source
- NVD
- EPSS
- EPSS 0.65 % · percentile 51 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- redhat
- NVD status
- Modified
Description
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.
Weaknesses (CWE)
- CWE-409 — Improper Handling of Highly Compressed Data (Data Amplification)
References
- https://access.redhat.com/errata/RHSA-2026:3947
- https://access.redhat.com/errata/RHSA-2026:3948
- https://access.redhat.com/errata/RHSA-2026:76128
- https://access.redhat.com/errata/RHSA-2026:76129
- https://access.redhat.com/errata/RHSA-2026:76130
- https://access.redhat.com/errata/RHSA-2026:76132
- https://access.redhat.com/errata/RHSA-2026:76134
- https://access.redhat.com/security/cve/CVE-2026-2575
- https://bugzilla.redhat.com/show_bug.cgi?id=2440149
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | MEDIUM 5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L | redhat |
| CVSS 3.1 | MEDIUM 5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L | NVD · secalert@redhat.com (Secondary) |
Advisories
- GHSA-xv6h-r36f-3gp5 — Keycloak: Denial of Service due to excessive SAMLRequest decompression
European references
- ENISA EUVD · EUVD-2026-12766
- GCVE · GCVE-0-2026-2575
Affected configurations (NVD CPE)
cpe:2.3:a:redhat:build_of_keycloak:*:*:*:*:*:*:*:*≥ 26.4 < 26.4.10
Affected products
| Product | Versions |
|---|---|
| Red Hat · Red Hat build of Keycloak 26.4 | unaffected 26.4.10-1 < * |
| Red Hat · Red Hat build of Keycloak 26.4 | unaffected 26.4-12 < * |
| Red Hat · Red Hat build of Keycloak 26.4 | unaffected 26.4-12 < * |
| Red Hat · Red Hat build of Keycloak 26.4.10 | |
| Red Hat · Red Hat Single Sign-On 7.6.13 | |
| Red Hat · Red Hat Single Sign-On 7.6 for RHEL 7 | unaffected 0:18.0.20-1.redhat_00001.1.el7sso < * |
| Red Hat · Red Hat Single Sign-On 7.6 for RHEL 8 | unaffected 0:18.0.20-1.redhat_00001.1.el8sso < * |
| Red Hat · Red Hat Single Sign-On 7.6 for RHEL 9 | unaffected 0:18.0.20-1.redhat_00001.1.el9sso < * |
| Red Hat · RHEL-8 based Middleware Containers | unaffected 7.6-85 < * |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |