{"id":"CVE-2025-46556","aliases":["GHSA-r3jf-hm7q-qfw5"],"url":"https://o3.security/vulnerability/CVE-2025-46556","summary":"MantisBT is Vulnerable to Denial-of-Service (DoS) attack via Excessive Note Length","details":"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:\n\n### Impact\n- The entire activity stream becomes unviewable (UI fails to render).\n- New notes cannot be displayed, effectively breaking all future collaboration on the issue.\n\n### Patches\nFixed in 2.27.2.\n\n### Workarounds\nNone\n\n### Credits\nThanks to Mazen Mahmoud (@TheAmazeng) for reporting the vulnerability.","published":"2025-11-04T00:20:28.193Z","modified":"2026-08-12T03:51:32.713462137Z","cvss":{"score":6.5,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Packagist","name":"mantisbt/mantisbt","fixedVersion":"2.27.2"}],"fix":{"url":"https://github.com/mantisbt/mantisbt/commit/c99a41272532ba49b5c8dccb7797afead9864234","label":"mantisbt/mantisbt@c99a412"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/46xxx/CVE-2025-46556.json"},{"type":"ADVISORY","url":"https://github.com/mantisbt/mantisbt/security/advisories/GHSA-r3jf-hm7q-qfw5"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-46556"},{"type":"FIX","url":"https://github.com/mantisbt/mantisbt/commit/c99a41272532ba49b5c8dccb7797afead9864234"},{"type":"FIX","url":"https://github.com/mantisbt/mantisbt/commit/d5cec6bffb44d54bd412c186b9baa409b1aa4238"},{"type":"FIX","url":"https://github.com/mantisbt/mantisbt/commit/e9119c68b4a0eaa0bbde3deb121e81f5f7157361"},{"type":"PACKAGE","url":"https://github.com/mantisbt/mantisbt"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:32.713462137Z"}}