CVE-2026-40874
mailcow: dockerized missing authorization on Forwarding Hosts delete action
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.
INFO
Published Date :
April 21, 2026, 8:17 p.m.
Last Modified :
April 21, 2026, 8:17 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-40874
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 4.0 | MEDIUM | [email protected] |
Solution
- Update mailcow to version 2026-03b.
- Verify administrator controls for deleting Forwarding Hosts.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-40874.
| URL | Resource |
|---|---|
| https://github.com/mailcow/mailcow-dockerized/security/advisories/GHSA-jjxh-rm7p-hjc3 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-40874 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-40874
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-40874 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-40874 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
Apr. 21, 2026
Action Type Old Value New Value Added 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. Added CVSS V4.0 AV:N/AC:H/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/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 Added CWE CWE-284 Added Reference https://github.com/mailcow/mailcow-dockerized/security/advisories/GHSA-jjxh-rm7p-hjc3