CVE-2026-40872

CRITICAL

mailcow: dockerized vulnerable to stored XSS in autodiscover logs email address field

Title source: cna

Description

mailcow: dockerized is an open source groupware/email suite based on docker. In versions prior to 2026-03b, the admin dashboard's Autodiscover logs render the EMailAddress value (logged as the "user" field) without HTML escaping. By submitting an unauthenticated Autodiscover request with a crafted EMailAddress containing HTML/JS, the payload is stored in Redis and executed when an admin views the Autodiscover logs. Version 2026-03b fixes the vulnerability.

References (1)

[X_Refsource_Confirm] https://github.com/mailcow/mailcow-dockerized/security/advisories/GHSA-f9xf-vc72-rcgm

Scores

CVSS v4 9.3

EPSS 0.0006

EPSS Percentile 19.1%

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:N

CISA SSVC

Vulnrichment

Exploitation poc

Automatable yes

Technical Impact total

Details

CWE

CWE-79 CWE-80

Status published

Products (1)

mailcow/mailcow-dockerized < 2026-03b

Published Apr 21, 2026

Tracked Since Apr 22, 2026