CVE-2026-120984

CRITICAL
Published Nov 7, 2026 Modified Nov 9, 2026 CWE-94

Description

A flaw was found in the Keycloak server's client management component. When a client is created or imported with authorization services enabled, the system fails to properly clear an internal session attribute used during the setup process. This allows an authenticated attacker with client management permissions to bypass security controls and upload a malicious JavaScript policy, which is then executed on the server when an authorization request is made. Successful exploitation could allow the attacker to run arbitrary code on the server, potentially compromising the entire system.

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CVSS v3.1 Score

9.1
CRITICAL
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

EPSS — Exploit Prediction

0.0042
Probability of exploitation
0.36%
Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-94 CWE-94

References

Frequently Asked Questions

What is CVE-2026-120984? +
A flaw was found in the Keycloak server's client management component. When a client is created or imported with authorization services enabled, the system fails to properly clear an internal session attribute used during the setup process. This allows an authenticated attacker with client management permissions to bypass security controls and upload a malicious JavaScript policy, which is then executed on the server when an authorization request is made. Successful exploitation could allow the attacker to run arbitrary code on the server, potentially compromising the entire system. It has a CVSS v3.1 base score of 9.1 (CRITICAL).
How severe is CVE-2026-120984? +
CVE-2026-120984 has a CVSS v3.1 score of 9.1 out of 10, rated CRITICAL. This is a critical vulnerability that should be patched immediately. The EPSS score is 0.0042, placing it in the 0th percentile for exploitation probability.
How do I check if I'm vulnerable to CVE-2026-120984? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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