Is CVE-2026-40871 actively exploited?

No active exploitation of CVE-2026-40871 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2026-40871 be exploited remotely?

Yes. CVE-2026-40871 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2026-40871?

CVE-2026-40871 has a CVSS score of 7.2 (HIGH).

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HIGH

CVE-2026-40871

CWE-20Published: April 21, 2026· Updated: Apr 22, 2026

7.2

CVSS v3.1

EPSS:0.04%probability of exploitation in 30 daysPercentile:12.7th

Official 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.

NVD Source

Technical Analysis

CVE-2026-40871 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

Exploitation requires high privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 7.2.