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TI-2026-82338 Aliases CVE-2026-117611GHSA-q2v4-c5p2-6gr4

Checkmk bundled CA stores trust compromised eMudhra certificates

Priority LOW 31CWE-1395Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
Present
Impact type
Spoofing
Confidentiality · integrity · availability
Low · Low · None
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-295.

Summary

Checkmk versions before 2.5.0p18, before 2.4.0p39, before 2.3.0p52 and 2.2.0 (EOL) bundle CA stores through certifi and webpki-roots that include a root CA trusting eMudhra (emSign) intermediate certificates whose private keys are public. This improper certificate validation (CWE-295) lets a remote attacker without privileges or user interaction present certificates that Checkmk accepts as trusted. The impact is a partial loss of confidentiality and integrity.

Written with Claude Haiku 5.5 from the sources below · 2026-10-29

Description from the CNA

Improper certificate validation in Checkmk <2.5.0p18, <2.4.0p39, <2.3.0p52 and 2.2.0 (EOL): the Certificate Authority stores bundled with "certifi" and "webpki-roots" include a root CA that trusts eMudhra (emSign) intermediate certificates whose private keys are public.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00238 14th percentileScored 2026-11-07
Fix Fixed Checkmk (Checkmk GmbH): 2.5.0p18, 2.4.0p39, 2.3.0p52

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
Checkmk GmbHCheckmk2.5.0 to before 2.5.0p18; 2.4.0 to before 2.4.0p39; 2.3.0 to before 2.3.0p52; 2.2.02.5.0p18, 2.4.0p39, 2.3.0p52Patch availableCNA
  • Checkmk VendorCheckmk GmbH Affected 2.5.0 to before 2.5.0p18; 2.4.0 to before 2.4.0p39; 2.3.0 to before 2.3.0p52; 2.2.0 Fixed in 2.5.0p18, 2.4.0p39, 2.3.0p52 Patch available CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:a:checkmk:checkmk:*:*:*:*:*:*:*:*——Checkmk GmbH
  • cpe:2.3:a:checkmk:checkmk:*:*:*:*:*:*:*:* Versions — — ·Checkmk GmbH

Remediation

Upgrade Checkmk to 2.5.0p18, 2.4.0p39 or 2.3.0p52. Checkmk 2.2.0 is end of life and has no fixed version.

Written with Claude Haiku 5.5 from the sources below · 2026-10-29

  • Fix · CNA Checkmk (Checkmk GmbH) Fixed in 2.5.0p18, 2.4.0p39, 2.3.0p52

Timeline

  1. 2026-10-29 Threatist record created from CVE-2026-117611
  2. 2026-10-29 Alias added: GHSA-q2v4-c5p2-6gr4
  3. 2026-10-29 CISA SSVC decision points changed
  4. 2026-10-29 Priority changed: MEDIUM → LOW

References

Advisory 3

  • TI-2025-26345 Cross Site Scripting through compromised remote site CVSS 4.0HIGH 8.5
  • TI-2025-40190 Cross-site scripting in HTML logs of Synthetic Monitoring test services CVSS 4.0HIGH 7.3
  • TI-2024-12762 Checkmk NagVis Remote Code Execution CVSS 3.1HIGH 7.2
  • TI-2024-12761 Checkmk NagVis Reflected Cross-site Scripting CVSS 3.1MEDIUM 5.4
  • TI-2024-19037 Brute-force protection ineffective for some login methods CVSS 3.1CRITICAL 9.8
  • TI-2024-05712 local IP restriction of internal HTTP endpoints CVSS 3.1CRITICAL 9.8
See all 128 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences