CVE-2026-40874 mailcow: dockerized missing authorization on Forwarding Hosts delete action
Any authenticated user can delete Forwarding Hosts in mailcow: dockerized, potentially disrupting mail services due to missing administrator verification.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-40874?
CVE-2026-40874 is a medium-severity missing authorization vulnerability in mailcow-dockerized, published on 21 Apr 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
mailcow: dockerized is an open source groupware/email suite based on docker. In versions prior to 2026-03b, no administrator verification takes place when deleting Forwarding Hosts with `/api/v1/delete/fwdhost`. Any authenticated user can call this API. Checks are only applied for edit/add actions, but deletion can still significantly disrupt the mail service. Version 2026-03b fixes the vulnerability.
Weakness: CWE-284
Which versions are affected by CVE-2026-40874?
How do I fix CVE-2026-40874?
No fix has been published for CVE-2026-40874 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-40874 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-40874 exists.
Sources
Also known as GHSA-jjxh-rm7p-hjc3.