CVE-2026-16100

MEDIUM CVSS 3.1: 6.5 EPSS 0.31%
Updated Aug 10, 2026
Prometheus
Parameter Value
CVSS 6.5 (MEDIUM)
Affected Versions 26.6 — 26.6.5
Fixed In 26.6.5
Type CWE-770 (Allocation Without Limits)
Vendor Prometheus
Public PoC No

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.

Attack Parameters

Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Privileges Required
Low
Basic privileges needed
User Interaction
None
No user interaction needed

Impact Assessment

Confidentiality
None
No data leak
Integrity
None
No data modification
Availability
High
Complete denial of service

CVSS Vector v3.1

Vulnerable Products 1

Configuration From (including) Up to (excluding)
Redhat Build_Of_Keycloak
cpe:2.3:a:redhat:build_of_keycloak:*:*:*:*:*:*:*:*
26.6 26.6.5