Cyber Resilience

CVE-2026-27181

Access Control in Mjdm Majordomo

Public PoCAccess Control
Published
18 February 2026
Modified
20 February 2026
CVSS Score v4 8.7
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/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 0.0071 50th percentile
Risk Priority 46 floored blend · peak EPSS

Summary

CVE-2026-27181 is a high-severity Missing Authorization (CWE-862) vulnerability in Mjdm Majordomo. Its CVSS base score is 8.7 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked in the top 50% 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 AC-24 (Access Control Decisions) and AC-25 (Reference Monitor) — 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-2026-27181, published on 2026-02-18, is a vulnerability in MajorDoMo (also known as Major Domestic Module), an open-source home automation platform. The issue lies in the market module's admin() method, which reads the 'mode' parameter from $_REQUEST using gr('mode') and assigns it directly to $this->mode at the start of execution. This bypasses authentication checks, exposing all mode-gated code paths—including uninstall functionality—to unauthenticated requests via the /objects/?module=market endpoint.

Unauthenticated attackers with network access can exploit this vulnerability through simple GET requests, requiring no privileges (PR:N), low attack complexity (AC:L), and no user interaction (UI:N). By setting mode=uninstall and specifying a module name, they trigger uninstallPlugin(), which deletes module records from the database, executes the module's uninstall() method via eval(), recursively deletes the module's directory and template files with removeTree(), and removes associated cycle scripts. Attackers can iterate through all module names to systematically wipe the entire MajorDoMo installation, resulting in high availability impact (A:H) with a CVSS v3.1 base score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H) and mapping to CWE-862 (Missing Authorization).

Advisories and patches are referenced in VulnCheck's analysis at https://www.vulncheck.com/advisories/majordomo-unauthenticated-module-uninstall-via-market-endpoint, a detailed post at https://chocapikk.com/posts/2026/majordomo-revisited/, and GitHub pull request #1177 at https://github.com/sergejey/majordomo/pull/1177.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

MajorDoMo (aka Major Domestic Module) allows unauthenticated arbitrary module uninstallation through the market module. The market module's admin() method reads gr('mode') from $_REQUEST and assigns it to $this->mode at the start of execution, making all mode-gated code paths reachable without…

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authentication via the /objects/?module=market endpoint. The uninstall mode handler calls uninstallPlugin(), which deletes module records from the database, executes the module's uninstall() method via eval(), recursively deletes the module's directory and template files using removeTree(), and removes associated cycle scripts. An attacker can iterate through module names and wipe the entire MajorDoMo installation with a series of unauthenticated GET requests.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
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.
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
T1548 Abuse Elevation Control Mechanism Privilege Escalation
Adversaries may circumvent mechanisms designed to control privilege elevation to gain higher-level permissions.
T1556 Modify Authentication Process Defense Impairment
Adversaries may modify authentication mechanisms and processes to access user credentials or enable otherwise unwarranted access to accounts.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2025-43838Shared CWE-862
CVE-2023-7268Shared CWE-862
CVE-2024-1158Shared CWE-862
CVE-2024-37427Shared CWE-862
CVE-2025-59561Shared CWE-862
CVE-2025-31533Shared CWE-862
CVE-2024-35725Shared CWE-862
CVE-2025-8565Shared CWE-862
CVE-2024-1804Shared CWE-862
CVE-2025-30017Shared CWE-862

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)
  • 5 hardening rules · 3 OS baselines
Validate
Prove the fix (OWASP ASVS)

Mitigating Controls (NIST 800-53 r5) AI

AC-3 directly requires enforcement of authorization decisions on every access request, structurally eliminating missing authorization checks.

AC-24 mandates that access control decisions are applied to each request, preventing bypass of authorization logic.

AC-25 requires a tamperproof, always-invoked reference monitor that ensures authorization checks cannot be omitted.

AC-6 reduces the set of actions reachable without proper authorization, limiting blast radius of missing checks.

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.AA-05 full match
prevents

Explicitly requires defining, enforcing, and reviewing authorizations and least privilege, directly preventing missing authorization checks.

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.

prevents

Requiring authentication and credentials before any access occurs eliminates the absence of authorization checks that would otherwise allow an unauthenticated actor to reach protected resources.

prevents

Requiring formal authorization of every access request before rights are granted ensures that checks for required permissions are performed, preventing missing authorization checks from being introduced.

prevents

Mandatory authorization checks and central records of granted rights ensure that every access attempt is preceded by an explicit decision rather than relying on missing checks.

mitigates

Segregating the approval of access rights from their implementation provides an independent check that reduces the impact of missing authorization checks in the resulting system configuration.

finds

By requiring competent outsiders to verify that every function enforces the need-to-know principle, the control lowers the likelihood that missing authorization checks persist undetected.

prevents

Defining authorization responsibilities and reviewing risk-treatment progress throughout the project lifecycle catches missing authorization checks before the system is deployed.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

Oracle Linux 8 (2 rules)
  • V-248581 OL 8 must require users to provide a password for privilege escalation. prevents CWE-862
  • V-252656 The OL 8 operating system must not be configured to bypass password requirements for privilege escalation. prevents CWE-862
RHEL 7 (2 rules)
  • V-251704 The Red Hat Enterprise Linux operating system must not be configured to bypass password requirements for privilege escalation. prevents CWE-862
  • V-204429 The Red Hat Enterprise Linux operating system must be configured so that users must provide a password for privilege escalation. prevents CWE-862

References