CVE-2026-27178: Mjdm Majordomo cross-site scripting (XSS) (CVSS 7.2)

Description

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.

CVSS 3.1 breakdown

Attack vectorNetwork

Attack complexityLow

Privileges requiredNone

User interactionNone

ScopeChanged

ConfidentialityLow

IntegrityLow

AvailabilityNone

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

Affected products

Mjdm Majordomoall versions

Remediation

No fixed version is recorded in the NVD data. Check the vendor advisory for the latest guidance.

References

https://chocapikk.com/posts/2026/majordomo-revisited/ExploitThird Party Advisory
https://github.com/sergejey/majordomo/pull/1177ExploitIssue Tracking
https://www.vulncheck.com/advisories/majordomo-stored-cross-site-scripting-via-method-parameters-to-shoutboxThird Party Advisory

Related CVEs

Recent high-severity vulnerabilities sharing a weakness type.

Frequently asked

Is CVE-2026-27178 being actively exploited?

CVE-2026-27178 is not in the CISA KEV catalog. A public exploit reference exists, so treat it as exploitable. Its EPSS exploit probability is 0.41%.

How severe is CVE-2026-27178?

CVE-2026-27178 has a CVSS 3.1 base score of 7.2, rated high. EPSS estimates a 0.41% probability of exploitation.

Which products are affected by CVE-2026-27178?

Affected products include Mjdm Majordomo.

How do I fix CVE-2026-27178?

Apply the vendor's patch or advisory guidance, then verify no affected versions remain across your devices.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2026-27178 against the real software inventory on every managed device, as each hourly inventory arrives. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

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