User Event Metrics Vulnerability in Keycloak by Red Hat
CVE-2026-16100

6.5MEDIUM

Key Information:

Vendor

Red Hat
Status
Red Hat Build Of Keycloak
Red Hat Data Grid 8
Red Hat Jboss Enterprise Application Platform Expansion Pack
Red Hat Single Sign-on 7
Vendor
CVE Published:
5 August 2026

What is CVE-2026-16100?

A vulnerability has been identified in Keycloak related to the recording of user-event metrics. When metrics are activated, error messages from failed account operations are captured as metric labels in Prometheus. These messages can incorporate user-generated input, such as nonexistent client IDs. Consequently, an authenticated user might exploit this flaw to generate an excessive number of unique metric entries, leading to memory exhaustion and potentially causing the affected service to crash or become unavailable.

References

https://access.redhat.com/security/cve/CVE-2026-16100
vdb-entryx_refsource_REDHAT
https://bugzilla.redhat.com/show_bug.cgi?id=2501730
issue-trackingx_refsource_REDHAT

CVSS V3.1

Score:
6.5
Severity:
MEDIUM
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
Low
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Red Hat would like to thank Paul Bottinelli (Trail of Bits) for reporting this issue.
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