Medium 5.3Published Sep 4, 2026

CVE-2026-15937Agent receiver certificate confusion allows authentication with a certificate issued for another endpoint

Updated under an hour ago (2026-10-19 09:00 UTC)

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It affects Checkmk GmbH Checkmk. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Every CVE for Checkmk GmbH Checkmk

Exploited in the last 30 days

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.

CVSS: 5.3 MEDIUM (v4.0, CNA)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
Weakness (CWE): CWE-295
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Checkmk
NVD analysis: Deferred
Record last updated: Sep 4, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Checkmk GmbH Checkmk checkmk:checkmk (from the name)	from 2.5.0 before 2.5.0p10	CNA record

References

https://checkmk.com/werk/19735vendor-advisory

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.