SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2023-26490

The Sync Job feature - which can be made available to standard users by assigning them the necessary permission - suffers from a shell command injection.

HIGH 8.8EPSS 2.22%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (2.22%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

mailcow is a dockerized email package, with multiple containers linked in one bridged network. The Sync Job feature - which can be made available to standard users by assigning them the necessary permission - suffers from a shell command injection. A malicious user can abuse this vulnerability to obtain shell access to the Docker container running dovecot. The imapsync Perl script implements all the necessary functionality for this feature, including the XOAUTH2 authentication mechanism. This code path creates a shell command to call openssl. However, since different parts of the specified user password are included without any validation, one can simply execute additional shell commands. Notably, the default ACL for a newly-created mailcow account does not include the necessary permission. The Issue has been fixed within the 2023-03 Update (March 3rd 2023). As a temporary workaround the Syncjob ACL can be removed from all mailbox users, preventing from creating or changing existing Syncjobs.

CVSS 3.1
8.8 HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS
2.22% probability · 82th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-78
Affected
mailcow/mailcow\
Source
security-advisories@github.com
EPSS trend
0%3%5%10 October 2026: 2.22%10 October 202610 October 2026

EPSS 2.2% since 10 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.