CVE-2025-46556: Mantisbt

High severity, CVSS 7.5. EPSS: 0.4% chance of exploitation in the next 30 days.

Mantis Bug Tracker (MantisBT) is an open source issue tracker. Versions 2.27.1 and below allow attackers to permanently corrupt issue activity logs by submitting extremely long notes (tested with 4,788,761 characters) due to a lack of server-side validation of note length. Once such a note is added, the activity stream UI fails to render; therefore, new notes cannot be displayed, effectively breaking all future collaboration on the issue. This issue is fixed in version 2.27.2.

Affected products

• Mantisbt Mantisbt: before 2.27.2 (fixed in 2.27.2)

Published 2025-11-04. Last modified 2026-06-17.