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

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.

Published: 2026-05-28 Last update: 2026-06-03 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2026-9796 is rated Low Risk (28.2/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.02%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-9796

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-28 0.02%

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-9796

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.5 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:H)
They need powerful rights—admin, root, or similar—before this pays off.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
1.2 5.2 [email protected]

Weakness enumeration for CVE-2026-9796

GitHub Security Advisory for CVE-2026-9796

GHSA-pq65-77rc-7r8c · Severity: medium — A flaw was found in Keycloak. An authenticated administrator with the `manage-clients` role can...

OS Trackers for CVE-2026-9796

vendor priority summary link
redhat medium https://access.redhat.com/security/cve/CVE-2026-9796

Affected software / configurations for CVE-2026-9796

Vendor Product Version Raw CPE
redhat build_of_keycloak cpe:2.3:a:redhat:build_of_keycloak:-:*:*:*:-:*:*:*

References for CVE-2026-9796

cvelogic Threat Intelligence