CVE-2025-46556
MantisBT Vulnerable to Denial-of-Service (DoS) via Excessive Note Length
Description
A lack of server-side validation for note length in MantisBT allows attackers to permanently corrupt issue activity logs by submitting extremely long notes (tested with 4,788,761 characters). Once such a note is added: ### Impact - The entire activity stream becomes unviewable (UI fails to render). - New notes cannot be displayed, effectively breaking all future collaboration on the issue. ### Patches Fixed in 2.27.2. ### Workarounds None ### Credits Thanks to Mazen Mahmoud (@TheAmazeng) for reporting the vulnerability.
How to fix CVE-2025-46556
To remediate CVE-2025-46556, upgrade the affected package to a fixed version below.
- —upgrade to 2.27.2 or later
Is CVE-2025-46556 being exploited?
Low — EPSS is 0.1%, meaning exploitation activity has not been observed at scale.
Affected packages (1)
- from 0, < 2.27.2
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | MEDIUM6.5 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |