CVE-2021-34357: QNAP Qmailagent

Medium severity, CVSS 6.1. EPSS: 0.7% chance of exploitation in the next 30 days.

A cross-site scripting (XSS) vulnerability has been reported to affect QNAP device running QmailAgent. If exploited, this vulnerability allows remote attackers to inject malicious code. We have already fixed this vulnerability in the following versions of QmailAgent: QmailAgent 3.0.2 ( 2021/08/25 ) and later

Affected products

• QNAP Qmailagent: before 3.0.2 (fixed in 3.0.2)

Published 2021-11-13. Last modified 2026-06-17.