CVE-2026-7307

Keycloak: keycloak: denial of service via specially crafted saml input

State: Published
Severity: 7.5 High
Published: May 19, 2026
Updated: Oct 6, 2026
Reserved: Apr 28, 2026

Description

A flaw was found in Keycloak. A remote, unauthenticated attacker can send a specially crafted XML input to the Security Assertion Markup Language (SAML) endpoint. This malicious input can cause high CPU usage and worker thread starvation, leading to a Denial of Service (DoS) where the server becomes unavailable.

Scores

CVSS	Score	Vector	Source
3.1	7.5 High	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H	redhat
3.1	7.5 High	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H	redhat-SADP

Weaknesses

CWE-1286 Improper Validation of Syntactic Correctness of Input

Affected Products

Product	Versions
keycloak	before 26.2.16Affected before 26.4.12Affected before 26.6.2Affected
Red Hat build of Keycloak 26.2Red Hat	26.2.16-1 and laterNot affected
Red Hat build of Keycloak 26.2Red Hat	26.2-21 and laterNot affected
Red Hat build of Keycloak 26.2Red Hat	26.2-21 and laterNot affected
Red Hat build of Keycloak 26.2.16Red Hat
Red Hat build of Keycloak 26.4Red Hat	26.4.12-1 and laterNot affected
Red Hat build of Keycloak 26.4Red Hat	26.4-17 and laterNot affected
Red Hat build of Keycloak 26.4Red Hat	26.4-17 and laterNot affected
Red Hat build of Keycloak 26.4.12Red Hat
Red Hat Single Sign-On 7.6.13Red Hat
Red Hat Single Sign-On 7.6 for RHEL 7Red Hat	0:18.0.20-1.redhat_00001.1.el7sso and laterNot affected
Red Hat Single Sign-On 7.6 for RHEL 8Red Hat	0:18.0.20-1.redhat_00001.1.el8sso and laterNot affected
Red Hat Single Sign-On 7.6 for RHEL 9Red Hat	0:18.0.20-1.redhat_00001.1.el9sso and laterNot affected
RHEL-8 based Middleware ContainersRed Hat	7.6-85 and laterNot affected

References

RHSA-2026:19594vendor-advisory
RHSA-2026:19595vendor-advisory
RHSA-2026:19596vendor-advisory
RHSA-2026:19597vendor-advisory
RHSA-2026:76128vendor-advisory
RHSA-2026:76129vendor-advisory
RHSA-2026:76130vendor-advisory
RHSA-2026:76132vendor-advisory
RHSA-2026:76134vendor-advisory
https://access.redhat.com/security/cve/CVE-2026-7307vdb-entry
RHBZ#2476526issue-tracking
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-7307.json

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