What is CVE-2022-31138?

CVE-2022-31138 is a high-severity vulnerability in Mailcow Mailcow\, classified under OS Command Injection. CVSS score: 8.8/10. Published 2022-07-11.

How severe is CVE-2022-31138?

High severity. CVSS v3 base score is 8.8 out of 10.

Is CVE-2022-31138 known to be exploited?

12 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

RCE in Mailcow Mailcow\

CVE-2022-31138

mailcow is a mailserver suite. Prior to mailcow-dockerized version 2022-06a, an extended privilege vulnerability can be exploited by manipulating the custom parameters regexmess, skipmess, regexflag, delete2foldersonly, delete2foldersbutnot, regextrans2, pipemess, or maxlinelengthcmd to execute arbitrary code. Users should update their mailcow instances with the `update.sh` script in the mailcow root directory to 2022-06a or newer to receive a patch for this issue. As a temporary workaround, the Syncjob ACL can be removed from all mailbox users, preventing changes to those settings.

Vulnerability class: Command Injection (OS Command Injection)

Published 2022-07-11 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.033 (88.3th percentile), scored 2026-10-23.

Low probability of exploitation in the next 30 days, but still tracked. 88th percentile — 88.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.033 · newest: 0.033 · change: -0.000

Affected products

Mailcow Mailcow\ — versions _dockerized
Mailcow Mailcow-Dockerized — versions < 2022-06a
Mailcow Mailcow\: Dockerized

Weakness classification (CWE)

CWE-78 — OS Command Injection

Public proof-of-concept exploits

References

github.com/mailcow/mailcow-dockerized/security/advisories/GHSA-vx9w-h33p-5vhc (Third Party Advisory, Mitigation)
github.com/mailcow/mailcow-dockerized/commit/d373164e13a14e058f82c9f1918a5612f3… (Patch, Third Party Advisory)
github.com/ly1g3/Mailcow-CVE-2022-31138 (Exploit, Third Party Advisory)
github.com/mailcow/mailcow-dockerized/releases/tag/2022-06a (Third Party Advisory, Release Notes)

Frequently asked questions

What is CVE-2022-31138?: CVE-2022-31138 is a high-severity vulnerability in Mailcow Mailcow\, classified under OS Command Injection. CVSS score: 8.8/10. Published 2022-07-11.
How severe is CVE-2022-31138?: High severity. CVSS v3 base score is 8.8 out of 10.
Is CVE-2022-31138 known to be exploited?: 12 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.