{"id":"GHSA-qj6w-v29q-4rgx","summary":"MantisBT is Vulnerable to Stored XSS in Custom Field Textarea Values","details":"Improper escaping of a textarea custom field's contents in the Update Issue page (bug_update_page.php) allows an attacker to inject HTML and, if CSP settings permit, execute arbitrary JavaScript when the page is loaded.\n\n### Impact\nSession theft leading to admin account takeover, full project data access.\n\n- Precondition: A textarea-type custom field must be configured for the project\n- Attacker: Authenticated user with bug report permission (low privilege)\n- Victim: Any user viewing the bug edit form, including administrators\n\n### Patches\n- 5fec0f448b7a7d7d539a6adb6dccceac4e4e4ab7\n\n### Workarounds\nThe default Content-Security Policy will block script execution.\n\n### References\n- https://mantisbt.org/bugs/view.php?id=37003\n- This is related to [CVE-2024-34081](https://github.com/advisories/GHSA-wgx7-jp56-65mq).\n\n### Credits\nThanks to the following security researchers for independently discovering and responsibly reporting the issue, and providing a patch to fix it.\n- Thanks to Nozomu Sasaki (Paul) (@morimori-dev)\n- Tristan Madani (@TristanInSec) from Talence Security","aliases":["CVE-2026-39960"],"modified":"2026-09-10T03:51:06.801643399Z","published":"2026-05-11T19:34:32Z","database_specific":{"severity":"MODERATE","github_reviewed":true,"github_reviewed_at":"2026-05-11T19:34:32Z","nvd_published_at":"2026-05-20T22:16:36Z","cwe_ids":["CWE-79"]},"references":[{"type":"WEB","url":"https://github.com/mantisbt/mantisbt/security/advisories/GHSA-qj6w-v29q-4rgx"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-39960"},{"type":"WEB","url":"https://github.com/mantisbt/mantisbt/commit/5fec0f448b7a7d7d539a6adb6dccceac4e4e4ab7"},{"type":"PACKAGE","url":"https://github.com/mantisbt/mantisbt"},{"type":"WEB","url":"https://mantisbt.org/bugs/view.php?id=37003"}],"affected":[{"package":{"name":"mantisbt/mantisbt","ecosystem":"Packagist","purl":"pkg:composer/mantisbt/mantisbt"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.28.2"}]}],"versions":["2.10.0","2.10.1","2.11.0","2.11.1","2.12.0","2.12.1","2.12.2","2.13.0","2.13.1","2.13.2","2.14.0","2.15.0","2.15.1","2.16.0","2.16.1","2.17.0","2.17.1","2.17.2","2.18.0","2.18.1","2.19.0","2.19.1","2.20.0","2.20.1","2.21.0","2.21.1","2.21.2","2.21.3","2.22.0","2.22.1","2.22.2","2.23.0","2.23.1","2.24.0","2.24.1","2.24.2","2.24.3","2.24.4","2.24.5","2.25.0","2.25.1","2.25.2","2.25.3","2.25.4","2.25.5","2.25.6","2.25.7","2.25.8","2.26.0","2.26.1","2.26.2","2.26.3","2.26.4","2.27.0","2.27.1","2.27.2","2.27.3","2.28.0","2.28.1","2.3.0","2.3.1","2.3.2","2.3.3","2.4.0","2.4.1","2.4.2","2.5.0","2.5.1","2.5.2","2.6.0","2.7.0","2.7.1","2.8.0","2.8.1","2.9.0","2.9.1"],"database_specific":{"last_known_affected_version_range":"\u003c= 2.28.1","source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/05/GHSA-qj6w-v29q-4rgx/GHSA-qj6w-v29q-4rgx.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N"}]}