VDB-358585 · CVE-2026-40871 · GHSA-r8fq-wrfm-cj2q

mailcow mailcow-dockerized prior 2026-03b API quarantine_category input validation

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5.8	$0-$5k	0.00

Summaryinfo

A vulnerability has been found in mailcow mailcow-dockerized and classified as problematic. The impacted element is an unknown function of the component API. This manipulation of the argument quarantine_category causes input validation. This vulnerability is registered as CVE-2026-40871. Remote exploitation of the attack is possible. No exploit is available. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in mailcow mailcow-dockerized. It has been declared as problematic. Affected by this vulnerability is an unknown part of the component API. The manipulation of the argument quarantine_category with an unknown input leads to a input validation vulnerability. The CWE definition for the vulnerability is CWE-20. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

mailcow: dockerized is an open source groupware/email suite based on docker. Versions prior to 2026-03b have a second-order SQL injection vulnerability in the quarantine_category field via the Mailcow API. The /api/v1/add/mailbox endpoint stores quarantine_category without validation or sanitization. This value is later used by quarantine_notify.py, which constructs SQL queries using unsafe % string formatting instead of parameterized queries. This results in a delayed (second-order) SQL injection when the quarantine notification job executes, allowing an attacker to inject arbitrary SQL. Using a UNION SELECT, sensitive data (e.g., admin credentials) can be exfiltrated and rendered inside quarantine notification emails. Version 2026-03b fixes the vulnerability.

The advisory is shared at github.com. This vulnerability is known as CVE-2026-40871 since 04/15/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation requires an enhanced level of successful authentication. Technical details are known, but no exploit is available.

Upgrading to version 2026-03b eliminates this vulnerability.

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

Virtualization Software

Vendor

mailcow

Name

mailcow-dockerized

Website

Product: https://github.com/mailcow/mailcow-dockerized/

CPE 2.3info

🔒

CPE 2.2info

🔒

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.9
VulDB Meta Temp Score: 5.8

VulDB Base Score: 4.7
VulDB Temp Score: 4.5
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 7.2
CNA Vector (GitHub_M): 🔒

CVSSv2info

AV	AC	Au	C	I	A
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💳	💳	💳	💳	💳	💳
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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Input validation
CWE: CWE-20
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: mailcow-dockerized 2026-03b

Timelineinfo

04/15/2026 CVE reserved
04/21/2026 +6 days Advisory disclosed
04/21/2026 +0 days VulDB entry created
04/21/2026 +0 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: GHSA-r8fq-wrfm-cj2q
Status: Confirmed

CVE: CVE-2026-40871 (🔒)
GCVE (CVE): GCVE-0-2026-40871
GCVE (VulDB): GCVE-100-358585
scip Labs: https://www.scip.ch/en/?labs.20171019

Entryinfo

Created: 04/21/2026 22:35
Changes: 04/21/2026 22:35 (65)
Complete: 🔍
Cache ID: 216::103