medium6.5
CVE-2025-46556
MantisBT Vulnerable to Denial-of-Service (DoS) via Excessive Note Length
Impact
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.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| composer | mantisbt/mantisbt | < 2.27.2 | 2.27.2 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Mantisbt | Mantisbt | before 2.27.2 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- 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
- https://github.com/advisories/GHSA-r3jf-hm7q-qfw5
- https://nvd.nist.gov/vuln/detail/CVE-2025-46556