CVE-2026-15937

Agent receiver certificate confusion allows authentication with a certificate issued for another endpoint

Published Sep 4, 2026 CVSS 4.0 · 5.3 Medium EPSS < 1% KEV · Not listed
Description
Improper certificate validation in Checkmk <2.5.0p10 allows a relay and a push agent that share the same UUID to reuse each other's mTLS certificate to authenticate against agent receiver endpoints in either direction, because the endpoints do not verify that the certificate was issued by their own root certificate.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
References
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description Improper certificate validation in Checkmk <2.5.0p10 allows a relay and a push agent that share the same UUID to reuse each other's mTLS certificate to authenticate against agent receiver endpoints in either direction, because the endpoints do not verify that the certificate was issued by their own root certificate.
Title Agent receiver certificate confusion allows authentication with a certificate issued for another endpoint
First Time appeared Checkmk
Checkmk checkmk
Weaknesses CWE-295
CPEs cpe:2.3:a:checkmk:checkmk:*:*:*:*:*:*:*:*
Vendors & Products Checkmk
Checkmk checkmk
References
Metrics cvssV4_0

{'score': 5.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
Checkmk
Published
Updated
Sep 4, 2026, 7:39 PM
Reserved
Jul 16, 2026, 8:40 AM
Status
Deferred
Published
Sep 4, 2026, 9:17 AM
Modified
Sep 8, 2026, 2:10 PM