CVE-2026-2575
Keycloak: keycloak: denial of service due to excessive samlrequest decompression
- Published
- Updated
- Reserved
- Assigned by
- redhat
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.
Timeline
ID reserved
By redhat
- 30 days later
· 30 days later
Published
- 7 months later
· 7 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| redhatCNA (assigner) | 3.1 | Medium5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L |
| NVDNVD · Modified | 3.1 | Medium5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L |
- EPSS (exploitation in 30 days)
- 0.66% · top 48% of all CVEs (9 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: yes · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.3.
Weakness
Affected products
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
All versions: unaffected
Red Hat · Red Hat Single Sign-On 7.6.13
All versions: unaffected
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 – < *
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- Mavenorg.keycloak:keycloak-saml-adapter-coreGHSA-xv6h-r36f-3gp5 (opens in a new tab)
- Mavenorg.keycloak:keycloak-saml-coreGHSA-xv6h-r36f-3gp5 (opens in a new tab)
- Mavenorg.keycloak:keycloak-servicesGHSA-xv6h-r36f-3gp5 (opens in a new tab)
What to do
Workaround: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
References (9)
- RHSA-2026:3947 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
- RHSA-2026:3948 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
- RHSA-2026:76128 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
- RHSA-2026:76129 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
- RHSA-2026:76130 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
- RHSA-2026:76132 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
- RHSA-2026:76134 (opens in a new tab)vendor-advisoryx_refsource_REDHAT
- https://access.redhat.com/security/cve/CVE-2026-2575 (opens in a new tab)vdb-entryx_refsource_REDHAT
- RHBZ#2440149 (opens in a new tab)issue-trackingx_refsource_REDHAT
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-12766 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-xv6h-r36f-3gp5 (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-2575)Record last updated .