Cyber Resilience

CVE-2026-33455

Checkmk 2.5.0

Published
10 April 2026
Modified
20 April 2026
Patch / advisory
View advisory
CVSS Score v4 5.3
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0018 7th percentile
Risk Priority 31 floored blend · peak EPSS

Summary

CVE-2026-33455 is a medium-severity Improper Neutralization of Delimiters (CWE-140) vulnerability in Checkmk Checkmk. Its CVSS base score is 5.3 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Content Injection (T1659); ranked at the 7th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

Livestatus injection in the monitoring quicksearch in Checkmk <2.5.0b4 allows an authenticated attacker to inject livestatus commands via the search query due to insufficient input sanitization in search filter plugins.

CWE(s)
CWE-140

Related Threats

MITRE ATT&CK Enterprise Techniques

T1659 Content Injection Initial Access
Adversaries may gain access and continuously communicate with victims by injecting malicious content into systems through online network traffic.
attack.mitre.org →
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2024-38865Same product: Checkmk Checkmk
CVE-2023-6157Same product: Checkmk Checkmk
CVE-2024-6542Same product: Checkmk Checkmk
CVE-2025-32918Same product: Checkmk Checkmk
CVE-2023-6156Same product: Checkmk Checkmk
CVE-2026-33457Same product: Checkmk Checkmk
CVE-2026-33456Same product: Checkmk Checkmk
CVE-2023-6251Same product: Checkmk Checkmk
CVE-2025-39664Same product: Checkmk Checkmk
CVE-2024-28828Same product: Checkmk Checkmk

Affected Assets

checkmk
checkmk
2.5.0

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

SA-11 Developer Testing and Evaluation good match

Developer testing and evaluation can discover missing or incorrect delimiter neutralization through targeted test cases.

SI-10 Information Input Validation good match

Input validation directly enforces neutralization of delimiters before they reach parsers or interpreters.

SA-8 Security and Privacy Engineering Principles partial match

Secure engineering principles include explicit requirements for proper delimiter handling and sanitization.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly require proper delimiter neutralization during input handling and output encoding.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing in development and acceptance can detect delimiter-related weaknesses before deployment.

A.8.25 Secure development life cycle partial match
prevents

Secure development life cycle incorporates practices that reduce the likelihood of delimiter-neutralization defects.

A.8.26 Application security requirements partial match
prevents

Application security requirements include input validation and output encoding that mitigate delimiter mishandling.

A.8.28 Secure coding partial match
prevents

Secure coding explicitly requires proper neutralization of delimiters to prevent injection and parsing flaws.

References