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Description

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.

PUBLISHED Reserved 2026-04-15 | Published 2026-04-21 | Updated 2026-04-21 | Assigner GitHub_M




HIGH: 7.2CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

Problem types

CWE-20: Improper Input Validation

CWE-89: Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection')

CWE-116: Improper Encoding or Escaping of Output

CWE-564: SQL Injection: Hibernate

Product status

< 2026-03b
affected

References

github.com/...erized/security/advisories/GHSA-r8fq-wrfm-cj2q exploit

github.com/...erized/security/advisories/GHSA-r8fq-wrfm-cj2q

cve.org (CVE-2026-40871)

nvd.nist.gov (CVE-2026-40871)

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