What is the CVSS score of CVE-2026-27178?

CVE-2026-27178 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%.

Which versions of PHP are affected by CVE-2026-27178?

MajorDoMo installations are vulnerable to stored cross-site scripting attacks that allow unauthenticated attackers to inject malicious code affecting all users who access the shoutbox feature.

Is there a public PoC exploit available for CVE-2026-27178?

Yes, a public proof-of-concept exploit is available for CVE-2026-27178. Prioritise patching immediately. EPSS: 0.0%.

How to fix or mitigate CVE-2026-27178?

Within 24 hours: Identify all MajorDoMo instances in your environment and assess internet accessibility; isolate internet-facing instances or restrict access via network controls. Within 7 days: Implement WAF rules blocking requests to /objects/?method= containing suspicious parameters; disable the shoutbox feature if not business-critical. Within 30 days: Evaluate alternative solutions or contact vendor for patched versions; conduct security code review of custom method implementations; perform user audit for evidence of exploitation.

PHP CVE-2026-27178

HIGH

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

2026-02-18 disclosure@vulncheck.com

PHP XSS Majordomo

7.2

CVSS 3.1 · NVD

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

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Changed

Confidentiality

Low

Integrity

Low

Availability

None

Lifecycle Timeline

Analysis Generated

Mar 12, 2026 - 21:55 vuln.today

PoC Detected

Feb 20, 2026 - 19:58 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 through method parameter injection into the shoutbox. The /objects/?method= endpoint allows unauthenticated execution of stored methods with attacker-controlled parameters. Default methods such as ThisComputer.VolumeLevelChanged pass the user-supplied VALUE parameter directly into the say() function, which stores the message raw in the shouts database table without escaping. The shoutbox widget renders stored messages without sanitization in both PHP rendering code and HTML templates. Because the dashboard widget auto-refreshes every 3 seconds, the injected script executes automatically when any administrator loads the dashboard, enabling session hijack through cookie exfiltration.

AnalysisAI

MajorDomo's shoutbox feature is vulnerable to stored XSS due to unsanitized user input in the /objects/?method= endpoint, allowing unauthenticated attackers to inject malicious scripts that persist in the database. When administrators access the auto-refreshing dashboard, the stored payload executes automatically, enabling session hijacking and cookie theft. Public exploit code exists for this vulnerability, and no patch is currently available.

Technical ContextAI

Classified as CWE-79 (Cross-site Scripting (XSS)). Affects the method component of Majordomo. MajorDoMo (aka Major Domestic Module) contains a stored cross-site scripting (XSS) vulnerability through method parameter injection into the shoutbox. The /objects/?method= endpoint allows unauthenticated execution of stored methods with attacker-controlled parameters. Default methods such as ThisComputer.VolumeLevelChanged pass the user-supplied VALUE parameter directly into the say() function, which stores the message raw in the shouts database table without escaping. The shoutbox widget rende

RemediationAI

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