CVE-2026-40872

CRITICAL

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

Title source: cna
STIX 2.1

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)

Core 1
Core References

Scores

CVSS v4 9.3
EPSS 0.0028
EPSS Percentile 20.3%
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

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