Cyber Resilience

CVE-2026-27175

RCE in Mjdm Majordomo

Published
18 February 2026
Modified
20 February 2026
CVSS Score v4 9.2
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/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 0.069 93th percentile
Risk Priority 64 floored blend · peak EPSS

Summary

CVE-2026-27175 is a critical-severity OS Command Injection (CWE-78) vulnerability in Mjdm Majordomo. Its CVSS base score is 9.2 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Command and Scripting Interpreter (T1059); ranked in the top 7% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

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.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2026-27175, published on 2026-02-18, is a critical unauthenticated OS command injection vulnerability (CWE-78, CVSS 9.8: AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H) affecting MajorDoMo (aka Major Domestic Module), an open-source home automation platform. The issue resides in the rc/index.php endpoint, where the user-supplied $param variable is interpolated directly into a command string within double quotes without proper sanitization, such as via escapeshellarg(). This command is then inserted into a database queue by the safe_exec() function, which performs no additional sanitization.

An unauthenticated remote attacker can exploit this via a race condition to achieve remote code execution. The web-accessible cycle_execs.php script, lacking authentication, retrieves queued commands and passes them directly to exec(). By first triggering cycle_execs.php—which purges the queue and enters a polling loop—the attacker can then inject a malicious command through the rc endpoint while the worker polls. Shell metacharacters in the payload expand inside the double-quoted string, enabling RCE within one second.

Advisories from VulnCheck and a Chocapikk blog post detail the issue, while mitigation is provided via GitHub pull request #1177 in the sergejey/majordomo repository, which addresses the injection flaw.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

MajorDoMo (aka Major Domestic Module) is vulnerable to unauthenticated OS command injection via rc/index.php. The $param variable from user input is interpolated into a command string within double quotes without sanitization via escapeshellarg(). The command is inserted into a database…

more

queue by safe_exec(), which performs no sanitization. The cycle_execs.php script, which is web-accessible without authentication, retrieves queued commands and passes them directly to exec(). An attacker can exploit a race condition by first triggering cycle_execs.php (which purges the queue and enters a polling loop), then injecting a malicious command via the rc endpoint while the worker is polling. The injected shell metacharacters expand inside double quotes, achieving remote code execution within one second.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1059 Command and Scripting Interpreter Execution
Adversaries may abuse command and script interpreters to execute commands, scripts, or binaries.
T1059.003 Windows Command Shell Execution
Adversaries may abuse the Windows command shell for execution.
T1059.004 Unix Shell Execution
Adversaries may abuse Unix shell commands and scripts for execution.
T1059.001 PowerShell Execution
Adversaries may abuse PowerShell commands and scripts for execution.
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.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-50917Same product: Mjdm Majordomo
CVE-2026-27174Same product: Mjdm Majordomo
CVE-2026-27179Same product: Mjdm Majordomo
CVE-2026-27178Same product: Mjdm Majordomo
CVE-2026-27177Same product: Mjdm Majordomo
CVE-2026-27176Same product: Mjdm Majordomo
CVE-2026-27181Same product: Mjdm Majordomo
CVE-2026-27180Same product: Mjdm Majordomo
CVE-2024-0292Shared CWE-78
CVE-2023-40479Shared CWE-78

Affected Assets

mjdm
majordomo
all versions

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V1.2.5
  • V1.2.8
  • V15.2.5

Mitigating Controls (NIST 800-53 r5) AI

Developer testing and evaluation can discover missing or incorrect command sanitization during development.

Input validation directly neutralizes or rejects special characters that would otherwise alter OS command structure.

Least privilege reduces the permissions available to any process that could be subverted by injected commands.

Least functionality restricts available OS commands and interpreters, limiting the blast radius of injection.

Secure engineering principles require proper neutralization of untrusted input before command construction.

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

PR.PS-06's SDLC practices directly require secure coding and input handling that blocks command-injection defects, yet the single broad outcome leaves many specific neutralization vectors and verification gaps unaddressed.

PR.PS-02 partial match
prevents

Routine patching/maintenance can remediate known command-injection CVEs in dependencies (partial forward) but does nothing to stop developers from introducing improper neutralization in custom code (none reverse).

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.

finds

Security testing and code review target insecure use of operating-system command interfaces, catching command-injection flaws introduced during development.

References