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Vulnerability · Published May 28, 2026 · Assigned by redhat

CVE-2026-9796Keycloak: keycloak: privilege escalation via time-of-check to time-of-use (toctou) vulnerability

Medium 6.5

In plain English

A medium-severity security flaw in Red Hat Build of Keycloak from Red Hat. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 12% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)6.5Medium
Exploit odds (30 days)0.2%top 87.5% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

A flaw was found in Keycloak. An authenticated administrator with the `manage-clients` role can exploit a Time-of-check to time-of-use (TOCTOU) vulnerability in the name-based admin role checks. This allows the attacker to escalate their privileges to `realm-admin` for all users within the realm, granting them extensive control over the system. The composite role relationship persists even after the attacker's own permissions are revoked and across system reboots.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Mavenorg.keycloak:keycloak-server26.6.4GHSA-pq65-77rc-7r8c

Affected products (as reported)

VendorProductVersions
Red Hat Red Hat build of Keycloak 26.6 see references
Red Hat Red Hat build of Keycloak 26.6 see references
Red Hat Red Hat build of Keycloak 26.6 see references
Red Hat Red Hat build of Keycloak 26.6.6 see references
Red Hat Red Hat Build of Keycloak see references

Weakness: CWE-367 · Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N

References