CVE-2025-46556

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.

CVSS 3.1

7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS

0.4% chance of exploitation in the next 30 days; higher than 35% of CVEs (scores of 2026-10-25)

CWE

CWE-770

Published

2025-11-04

Modified

2026-10-19

Record from

the NVD, synced 2026-10-19

Affected

• mantisbt:mantisbt

References

• https://github.com/mantisbt/mantisbt/commit/c99a41272532ba49b5c8dccb7797afead9864234
• https://github.com/mantisbt/mantisbt/commit/d5cec6bffb44d54bd412c186b9baa409b1aa4238
• https://github.com/mantisbt/mantisbt/commit/e9119c68b4a0eaa0bbde3deb121e81f5f7157361
• https://github.com/mantisbt/mantisbt/security/advisories/GHSA-r3jf-hm7q-qfw5

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