What is the CVSS score of CVE-2026-27177?

CVE-2026-27177 has a CVSS 3.1 base score of 7.2 (High). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N. EPSS exploitation probability: 0.0%.

Is there a public PoC exploit available for CVE-2026-27177?

Yes, a public proof-of-concept exploit is available for CVE-2026-27177. Prioritise patching immediately. EPSS: 0.0%.

How to fix or mitigate CVE-2026-27177?

Within 24 hours: Identify all MajorDoMo deployments and assess exposure by cataloging which IoT devices interact with the /objects/?op=set endpoint. Within 7 days: Implement WAF rules to block malicious payloads on the endpoint and enable request logging; segment MajorDoMo instances from critical networks. Within 30 days: Evaluate alternative vendors or community patches; establish input validation and output encoding at the application layer if vendor patch becomes available.

Majordomo CVE-2026-27177

HIGH

Cross-site Scripting (XSS) (CWE-79)

2026-02-18 disclosure@vulncheck.com

PHP XSS IoT Majordomo Mjdm

7.2

CVSS 3.1 · NVD

View

Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain

Access

Send crafted HTTP request to /objects/?op=set endpoint
Delivery

Inject malicious JavaScript in property value
Exploit

Store XSS payload in database
Execution

Admin views property editor
Impact

Execute stored JavaScript in admin session

Vulnerability Assessment

Weakness	CWE CWE-79 OWASP Top 10:2025 A05:2025 - Injection ASVS 5.0 V1 - Encoding and Sanitization Output encoding, context-aware escaping MITRE ATT&CK 2 techniques across 2 tactics: Initial Access, Execution The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. Sign in to read
Exploitation Conditions	MajorDoMo with intentionally unauthenticated /objects/?op=set endpoint enabled for IoT device integration. Admin must access property editor in admin panel to trigger stored XSS payload execution.
Impact	CVSS 7.2 (HIGH). Attack vector: Network. Complexity: Low. Privileges required: None. User interaction: None. Exploitation no authentication required. Public exploit/POC available.
Exploit ScenarioDerived	An attacker without authentication could exploit this vulnerability to compromise the affected system.

This Week Schedule remediation this week. Why: HIGH severity (CVSS 7.0-8.9).

No patch listed yet 0.0% exploitation probability (EPSS)

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AnalysisAIv1 – Mar 12, 2026

MajorDoMo's unauthenticated /objects/?op=set endpoint fails to sanitize property values, allowing remote attackers to inject stored XSS payloads that execute when administrators access the property editor, with public exploit code available. The vulnerability is compounded by session cookies lacking HttpOnly protection, enabling attackers to enumerate properties via the /api.php/data/ endpoint and hijack admin sessions through JavaScript exfiltration.

Earlier versions of this analysis (1)

v1 Mar 12, 2026 - 21:55 CVSS 7.2

RemediationAI

Monitor vendor advisories for a patch. Implement output encoding and Content Security Policy headers. Restrict network access to the affected service where possible.

Affects your stack

Find out whether the stacks and servers you run are on an affected version.

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

Classified as CWE-79 (Cross-site Scripting (XSS)). Affects Majordomo. MajorDoMo (aka Major Domestic Module) contains a stored cross-site scripting (XSS) vulnerability via the /objects/?op=set endpoint, which is intentionally unauthenticated for IoT device integration. User-supplied property values are stored raw in the database without sanitization. When an administrator views the property editor in the admin panel, the stored values are rendered without escaping in both a paragraph tag (SOURCE field) and a textarea element (VALUE field). The XSS fires on page loa

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Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

NVD PRIMARY 7.2 HIGH

AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Changed

Confidentiality

Low

Integrity

Low

Availability

None

Lifecycle Timeline

PoC Detected

Feb 20, 2026 - 20:00 vuln.today

Public exploit code

CVE Published

Feb 18, 2026 - 22:16 nvd

HIGH 7.2

DescriptionCVE.org

MajorDoMo (aka Major Domestic Module) contains a stored cross-site scripting (XSS) vulnerability via the /objects/?op=set endpoint, which is intentionally unauthenticated for IoT device integration. User-supplied property values are stored raw in the database without sanitization. When an administrator views the property editor in the admin panel, the stored values are rendered without escaping in both a paragraph tag (SOURCE field) and a textarea element (VALUE field). The XSS fires on page load without requiring any click from the admin. Additionally, the session cookie lacks the HttpOnly flag, enabling session hijack via document.cookie exfiltration. An attacker can enumerate properties via the unauthenticated /api.php/data/ endpoint and poison any property with malicious JavaScript.

Articles & Coverage 1

vulnerability.circl.lu MajorDoMo Multiple Critical RCE Vulnerabilities (CVE-2026-27174 to CVE-2026-27181) Feb 19, 2026

Executive ViewAI

Why It Matters

MajorDoMo contains a stored cross-site scripting vulnerability in an intentionally unauthenticated IoT integration endpoint, allowing attackers to inject malicious code that executes when users access affected properties. This impacts any organization using MajorDoMo for home automation or IoT management, creating risk of user account compromise, credential theft, and lateral movement within connected systems.

Business Impact: High

Compensating Controls

Deploy Web Application Firewall (WAF) with rules blocking script payloads (script tags, event handlers, encoded variations) on /objects/?op=set endpoint; implement network segmentation to isolate MajorDoMo from sensitive systems; disable or restrict access to the unauthenticated endpoint if IoT integration is not actively required; enable comprehensive logging and monitoring for suspicious property value submissions; consider deploying a reverse proxy with input sanitization; monitor vendor advisories and community patches for interim fixes.

Threat Intelligence Overview

EPSS Score

0.0%

Top 93% exploitable

Exploit

POC

Public exploit code exists

Data Quality

4 sources

Confidence: Medium

NVD

CVE.org

EPSS

GitHub

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue

Severity HIGH

CISA KEV No

Public POC Yes

EPSS 0.0%

Patch available No

Active threat No

Deciding rule

HIGH severity (CVSS 7.0-8.9)

What every action level means

Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.

Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.

This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.

This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.

Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.