CVE-2026-16100

What it is

A flaw was found in the user-event metrics recording of Keycloak. When metrics are enabled, the system records raw error messages from failed account operations as Prometheus metric labels. Because these error messages can include user-supplied input like nonexistent client IDs, an authenticated user can create a massive number of unique metric entries, eventually exhausting system memory and causing the service to crash or become unavailable.

At a glance

Exploitability

Can be exploited over the network with a low-privilege account. High risk of service disruption.

Exploit odds

0.6% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-08-05 15:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-08-31 12:17 UTC Last updatedMost recent change to the record

Details

Published

2026-08-05 15:16 UTC

Last modified

2026-08-31 12:17 UTC

Exploit probability

0.6% · EPSS, next 30 days

Weakness

CWE-770 · Allocation without limits

Record status

Modified

Affected

• Redhat Build Of Keycloak < 26.6.5

Attack profile CVSS 3.1 · 6.5

Attack vector

Network

Complexity

Low

Privileges needed

Low

User interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High