CVE-2021-21439: Otrs

Medium severity, CVSS 6.5. EPSS: 0.9% chance of exploitation in the next 30 days.

DoS attack can be performed when an email contains specially designed URL in the body. It can lead to the high CPU usage and cause low quality of service, or in extreme case bring the system to a halt. This issue affects: OTRS AG ((OTRS)) Community Edition 6.0.x version 6.0.1 and later versions. OTRS AG OTRS 7.0.x version 7.0.26 and prior versions; 8.0.x version 8.0.13 and prior versions.

Affected products

• Otrs Otrs: from 6.0.1, up to and including 6.0.30; from 7.0.0, before 7.0.27 (fixed in 7.0.27); from 8.0.0, before 8.0.14 (fixed in 8.0.14)

Published 2021-06-14. Last modified 2026-06-17.