Unauthenticated Deletion Vulnerability in mailcow: dockerized Email Suite
CVE-2026-40874

6MEDIUM

Key Information:

Vendor

Mailcow

Status
Mailcow-dockerized
Vendor
CVE Published:
21 April 2026

What is CVE-2026-40874?

The mailcow: dockerized email suite, a popular open-source solution, is subject to an unauthenticated API access vulnerability. In earlier versions, specifically before 2026-03b, there are no administrative checks enforced when an authenticated user attempts to delete Forwarding Hosts via the /api/v1/delete/fwdhost endpoint. This lack of validation can allow any authenticated user to disrupt email services significantly by deleting essential forwarding configurations, posing a risk to business continuity. The latest version, 2026-03b, addresses and fixes this security concern.

Affected Version(s)

mailcow-dockerized < 2026-03b

References

https://github.com/mailcow/mailcow-dockerized/security/ad...
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CVSS V4

Score:
6
Severity:
MEDIUM
Confidentiality:
None
Integrity:
None
Availability:
High
Attack Vector:
Network
Attack Complexity:
High
Attack Required:
Physical
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.