CVE intelligence and bounded remediation

CVE-2026-40871 — mailcow: dockerized is an open source groupware/email suite based on docker

High CVSS 7.2

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.

Severity
High
CVSS
7.2 (3.1)
Published
2026-04-21
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-20, CWE-89, CWE-116, CWE-564

Affected products

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Matched remediation archetype

SQL and data-query injection

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Check exposure

  • Trace request, message, file, and stored values into SQL, ORM query fragments, filters, sort expressions, and other data-query languages.
  • Inventory database roles, reachable schemas, multi-tenant boundaries, and whether stacked or administrative operations are enabled.
  • Check both direct queries and second-order use of previously stored values.

Remediate safely

  • Use parameterized queries or safe query builders for all values; map identifiers and operators through explicit allowlists.
  • Remove raw query concatenation and give the application account only the tables and operations it requires.
  • Update affected data-access components and add regression tests for query structure preservation with inert edge-case inputs.

Authoritative sources

Complete CVE record and remediation plan

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