What’s Vulnerable › Vulnerabilities

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

• Severity: medium (CVSS 6.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-05-28 · updated 2026-10-26
• Weakness: CWE-367

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 products

• Red Hat build of Keycloak 26.4: all versions

References

• https://access.redhat.com/errata/RHSA-2026:56523
• https://access.redhat.com/errata/RHSA-2026:56524
• https://access.redhat.com/security/cve/CVE-2026-9796
• https://bugzilla.redhat.com/show_bug.cgi?id=2482464

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