{"id":"CVE-2026-40596","aliases":["GHSA-j3v9-553h-x28j"],"url":"https://o3.security/vulnerability/CVE-2026-40596","summary":"MantisBT is vulnerable to XSS and potential account takeover via user font family preference update","details":"Any authenticated user can inject arbitrary HTML via updating their account's font family.\n\n### Impact\nCross-site scripting.\nThe injected payload will be reflected in every MantisBT page.\n\nLeveraging another vulnerability (CSP bypass, see [GHSA-9c3j-xm6v-j7j3](https://github.com/mantisbt/mantisbt/security/advisories/GHSA-9c3j-xm6v-j7j3)), the attacker could achieve account takeover.\n\n### Patches\n- 9e8409cdd979eba86ef532756fc47c1d8112d22d\n\n### Workarounds\nNone\n\n### Credits\nThanks to siunam (Tang Cheuk Hei) for discovering and responsibly reporting the issue.","published":"2026-05-22T19:25:32.812Z","modified":"2026-08-12T03:51:27.154256587Z","cvss":null,"epss":{"score":0.00424,"percentile":0.35112,"asOf":"2026-08-24"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Packagist","name":"mantisbt/mantisbt","fixedVersion":"2.28.2"}],"fix":{"url":"https://github.com/mantisbt/mantisbt/commit/9e8409cdd979eba86ef532756fc47c1d8112d22d","label":"mantisbt/mantisbt@9e8409c"},"references":[{"type":"WEB","url":"https://mantisbt.org/bugs/view.php?id=37011"},{"type":"WEB","url":"https://mantisbt.org/bugs/view.php?id=37016"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/40xxx/CVE-2026-40596.json"},{"type":"ADVISORY","url":"https://github.com/mantisbt/mantisbt/security/advisories/GHSA-9c3j-xm6v-j7j3"},{"type":"ADVISORY","url":"https://github.com/mantisbt/mantisbt/security/advisories/GHSA-j3v9-553h-x28j"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-40596"},{"type":"FIX","url":"https://github.com/mantisbt/mantisbt/commit/9e8409cdd979eba86ef532756fc47c1d8112d22d"},{"type":"PACKAGE","url":"https://github.com/mantisbt/mantisbt"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:27.154256587Z"}}