CVE-2025-58126: Checkmk · Improper Certificate Validation
Source CVE Database V5
Not known to be exploited · CVSS 6.9 Medium.
Data as of 26 Oct 2026, 09:08 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 1% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:H/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 28 Aug 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
AI-suggested
Organizations should immediately review their deployment of the Checkmk Exchange plugin for VMware vSAN and assess network exposure. Specific mitigations include: 1) Implement strict network segmentation and use encrypted VPN tunnels to limit the possibility of MitM attacks within internal networks. 2) Monitor network traffic for unusual TLS certificate anomalies or unexpected certificate chains related to VMware vSAN endpoints. 3) Temporarily disable or restrict the use of the affected plugin if possible until a patch is released. 4) Validate and enforce certificate pinning or strict certificate validation policies in the monitoring environment if configurable. 5) Keep abreast of vendor advisories from Checkmk and VMware for patches or updates addressing this vulnerability and apply them promptly. 6) Conduct internal audits of TLS configurations and certificate management practices to ensure robust validation mechanisms are in place. 7) Educate network and security teams about the risks of MitM attacks in internal environments and the importance of certificate validation.
Description
Improper Certificate Validation in Checkmk Exchange plugin VMware vSAN allows attackers in MitM position to intercept traffic.