RCE in Mjdm Majordomo
CVE-2026-27175
MajorDoMo (aka Major Domestic Module) is vulnerable to unauthenticated OS command injection via rc/index.php. The $param variable from user input is interpolated into a command string within double quotes without sanitization via escapeshellarg(). The command is inserted into a database queue by safe_exec(), which performs no sanitization. The cycle_execs.php script, which is web-accessible without authentication, retrieves queued commands and passes them directly to exec(). An attacker can exploit a race condition by first triggering cycle_execs.php (which purges the queue and enters a polling loop), then injecting a malicious command via the rc endpoint while the worker is polling. The injected shell metacharacters expand inside double quotes, achieving remote code execution within one second.
Vulnerability class: Command Injection (OS Command Injection)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.070 (94.0th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 94th percentile — 94.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.069 · newest: 0.070 · change: +0.002
Affected products
- Mjdm Majordomo
- Sergejey Majordomo — versions 0
Weakness classification (CWE)
Public proof-of-concept exploits
References
- chocapikk.com/posts/2026/majordomo-revisited/ (Exploit, Third Party Advisory, third-party-advisory)
- github.com/sergejey/majordomo/pull/1177 (issue-tracking, Exploit, patch, Issue Tracking)
- www.vulncheck.com/advisories/majordomo-command-injection-in-rcindexphp-via-race… (Third Party Advisory, third-party-advisory)
Frequently asked questions
- What is CVE-2026-27175?
- CVE-2026-27175 is a critical-severity vulnerability in Mjdm Majordomo, classified under OS Command Injection. CVSS score: 9.8/10. Published 2026-02-18.
- How severe is CVE-2026-27175?
- Critical severity. CVSS v3 base score is 9.8 out of 10.
- Is CVE-2026-27175 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.