XSS in Mjdm Majordomo

CVE-2026-27177

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.

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.002 (9.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-27177?
CVE-2026-27177 is a high-severity vulnerability in Mjdm Majordomo, classified under Cross-site Scripting. CVSS score: 7.2/10. Published 2026-02-18.
How severe is CVE-2026-27177?
High severity. CVSS v3 base score is 7.2 out of 10.