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CVE-2026-16100

Keycloak-services: keycloak-services: unbounded metric cardinality in user event metrics via request-controlled error text

Published: Aug 5, 2026Updated: Aug 6, 2026 Sources: CVE List NVDCWE-770
6.5MEDIUM
NVD MITRE
EPSS Score
0.3%
Top 77.2%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Workaround Only
Self-Check
OpenVAS

Description

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.

No summary for this CVE yet.

CVSS Vector Breakdown

AV:NAC:LPR:LUI:NS:UC:NI:NA:H
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:LPrivileges Required
Low
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:NConfidentiality
None
I:NIntegrity
None
A:HAvailability
High
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Weaknesses

CWE-770

Affected Products

Red Hat
commercial·US
Red Hat build of Keycloak 26.6On-prem
Security Products / identity-access-mgmt
Red Hat build of Keycloak 26.6.5On-prem
Operating Systems / linux-distro
Red Hat Data Grid 8On-premDatabase
Databases / cache-message-queue
Red Hat JBoss Enterprise Application Platform Expansion PackOn-premOS
Operating Systems / linux-distro
Red Hat Single Sign-On 7On-premSecurity Product
Security Products / identity-access-mgmt

Exploitability

Workaround Available
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Attack Graph

Products CVE Techniques Tactics

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MITRE ATT&CK

1 technique
Impact
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References

https://access.redhat.com/errata/RHSA-2026:50848
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:50849
access.redhat.com
https://access.redhat.com/security/cve/CVE-2026-16100
access.redhat.com
and 1 more references View all →

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