medium5.3
CVE-2026-2575
Keycloak: Denial of Service due to excessive SAMLRequest decompression
Impact
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.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| maven | org.keycloak:keycloak-saml-adapter-core | < 26.5.4 | 26.5.4 |
| maven | org.keycloak:keycloak-saml-core | < 26.5.4 | 26.5.4 |
| maven | org.keycloak:keycloak-services | < 26.5.4 | 26.5.4 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Redhat | Build Of Keycloak | from 26.4 before 26.4.10 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- 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
- https://github.com/advisories/GHSA-xv6h-r36f-3gp5
- https://nvd.nist.gov/vuln/detail/CVE-2026-2575
- https://github.com/keycloak/keycloak/issues/46372
- https://github.com/keycloak/keycloak/commit/4f90ef67f698dfb45df0d2f4981271a7c8b47f04