{"id":"CVE-2026-40597","aliases":["EUVD-2026-31496","GHSA-9c3j-xm6v-j7j3"],"status":"published","title":"MantisBT has a Content Security Policy bypass via attachments","description":"Mantis Bug Tracker (MantisBT) is an open source issue tracker. In versions 2.28.1 and below, given any pre-existing XSS / HTML injection vulnerability, an attacker can bypass the Content Security Policy's script-src directive by uploading a crafted attachment to any issue that, when accessed via the file_download.php link, will be downloaded with a valid JavaScript MIME type resulting in script execution. The uploaded payload must be sniffed as a valid JavaScript MIME type by PHP finfo (see file_create_finfo() API function). Non-JavaScript MIME types will not get imported in a \u003cscript\u003e tag by the browser, due to response header X-Content-Type-Options being set to nosniff, which requires all imported JavaScript files to be a valid JavaScript MIME type. This issue has been fixed in version 2.28.2.","severity":{"version":"4.0","score":7.6,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.00498,"percentile":0.43201,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-358","CWE-79"],"published":"2026-05-11T19:34:48Z","modified":"2026-10-28T02:31:13Z","fixes":[{"ecosystem":"Packagist","package":"mantisbt/mantisbt","fixed_in":["2.28.2"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"Packagist","package":"mantisbt/mantisbt","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"2.28.1"},{"fixed":"2.28.2"}]}]},{"source":"osv","ecosystem":"Packagist","package":"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"]}],"products":[{"vendor":"mantisbt","product":"mantisbt"}],"references":[{"url":"https://github.com/mantisbt/mantisbt/security/advisories/GHSA-9c3j-xm6v-j7j3","tags":["x_refsource_CONFIRM","advisory","web"]},{"url":"https://github.com/mantisbt/mantisbt/commit/9e3bee2e7b909f4e3596985892b8bc8bee9e0bfe","tags":["x_refsource_MISC","fix","web"]},{"url":"https://mantisbt.org/bugs/view.php?id=37016","tags":["x_refsource_MISC","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-40597","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-9c3j-xm6v-j7j3"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/40xxx/CVE-2026-40597.json","tags":["advisory"]},{"url":"https://github.com/mantisbt/mantisbt","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-40597","title":"MantisBT has a Content Security Policy bypass via attachments","description":"Mantis Bug Tracker (MantisBT) is an open source issue tracker. In versions 2.28.1 and below, given any pre-existing XSS / HTML injection vulnerability, an attacker can bypass the Content Security Policy's script-src directive by uploading a crafted attachment to any issue that, when accessed via the file_download.php link, will be downloaded with a valid JavaScript MIME type resulting in script execution. The uploaded payload must be sniffed as a valid JavaScript MIME type by PHP finfo (see file_create_finfo() API function). Non-JavaScript MIME types will not get imported in a \u003cscript\u003e tag by the browser, due to response header X-Content-Type-Options being set to nosniff, which requires all imported JavaScript files to be a valid JavaScript MIME type. This issue has been fixed in version 2.28.2.","status":"published","published":"2026-05-22T19:29:46.728Z","modified":"2026-05-26T19:06:00.401Z","cvss":[{"version":"4.0","score":7.6,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N","level":"high","assessor":"cna"}],"cwes":["CWE-79","CWE-358"],"updated_at":"2026-11-02T13:43:00.288193Z"}],"euvd":[{"id":"EUVD-2026-31496","description":"Mantis Bug Tracker (MantisBT) is an open source issue tracker. In versions 2.28.1 and below, given any pre-existing XSS / HTML injection vulnerability, an attacker can bypass the Content Security Policy's script-src directive by uploading a crafted attachment to any issue that, when accessed via the file_download.php link, will be downloaded with a valid JavaScript MIME type resulting in script execution. The uploaded payload must be sniffed as a valid JavaScript MIME type by PHP finfo (see file_create_finfo() API function). Non-JavaScript MIME types will not get imported in a \u003cscript\u003e tag by the browser, due to response header X-Content-Type-Options being set to nosniff, which requires all imported JavaScript files to be a valid JavaScript MIME type. This issue has been fixed in version 2.28.2.","status":"published","published":"2026-05-22T19:29:46Z","modified":"2026-05-26T19:06:00Z","cvss":[{"version":"4.0","score":7.6,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N","level":"high"}],"updated_at":"2026-11-02T18:21:06.423934Z"}],"ghsa":[{"id":"GHSA-9c3j-xm6v-j7j3","title":"MantisBT has a Content Security Policy bypass via attachments","description":"Given any pre-existing XSS / HTML injection vulnerability, an attacker can bypass the Content Security Policy's _script-src_ directive by uploading a crafted attachment to any issue that, when accessed via the _file_download.php_ link, will be downloaded with a valid JavaScript MIME type resulting in script execution.\n\nThe uploaded payload must be sniffed as a valid JavaScript MIME type by PHP finfo (see file_create_finfo() API function). Non-JavaScript MIME types will not get imported in a `\u003cscript\u003e` tag by the browser, due to response header X-Content-Type-Options being set to _nosniff_, which requires all imported JavaScript files to be a valid JavaScript MIME type.\n\n### Impact\nCross-site scripting\n\n### Patches\n- 9e3bee2e7b909f4e3596985892b8bc8bee9e0bfe\n\n### Workarounds\nNone\n\n### Credits\nThanks to siunam (Tang Cheuk Hei) for discovering and responsibly reporting the issue.","status":"published","published":"2026-05-11T19:34:48Z","modified":"2026-06-08T23:20:24Z","cvss":[{"version":"4.0","score":7.6,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N","level":"high"}],"cwes":["CWE-79","CWE-358"],"updated_at":"2026-11-02T14:40:20.187636Z"}],"nvd":[{"id":"CVE-2026-40597","description":"Mantis Bug Tracker (MantisBT) is an open source issue tracker. In versions 2.28.1 and below, given any pre-existing XSS / HTML injection vulnerability, an attacker can bypass the Content Security Policy's script-src directive by uploading a crafted attachment to any issue that, when accessed via the file_download.php link, will be downloaded with a valid JavaScript MIME type resulting in script execution. The uploaded payload must be sniffed as a valid JavaScript MIME type by PHP finfo (see file_create_finfo() API function). Non-JavaScript MIME types will not get imported in a \u003cscript\u003e tag by the browser, due to response header X-Content-Type-Options being set to nosniff, which requires all imported JavaScript files to be a valid JavaScript MIME type. This issue has been fixed in version 2.28.2.","status":"published","published":"2026-05-22T20:16:34.347Z","modified":"2026-07-23T16:10:00.137Z","cvss":[{"version":"4.0","score":7.6,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"high","assessor":"secondary"}],"cwes":["CWE-79","CWE-358"],"updated_at":"2026-11-02T14:12:20.131508Z"}],"osv":[{"id":"CVE-2026-40597","title":"MantisBT has a Content Security Policy bypass via attachments","description":"Mantis Bug Tracker (MantisBT) is an open source issue tracker. In versions 2.28.1 and below, given any pre-existing XSS / HTML injection vulnerability, an attacker can bypass the Content Security Policy's script-src directive by uploading a crafted attachment to any issue that, when accessed via the file_download.php link, will be downloaded with a valid JavaScript MIME type resulting in script execution. The uploaded payload must be sniffed as a valid JavaScript MIME type by PHP finfo (see file_create_finfo() API function). Non-JavaScript MIME types will not get imported in a \u003cscript\u003e tag by the browser, due to response header X-Content-Type-Options being set to nosniff, which requires all imported JavaScript files to be a valid JavaScript MIME type. This issue has been fixed in version 2.28.2.","status":"published","published":"2026-05-22T19:29:46.728Z","modified":"2026-10-28T02:31:13.301546805Z","cvss":[{"version":"4.0","score":7.6,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N","level":"high"}],"cwes":["CWE-358","CWE-79"],"updated_at":"2026-11-02T15:45:03.424067Z"},{"id":"GHSA-9c3j-xm6v-j7j3","title":"MantisBT has a Content Security Policy bypass via attachments","description":"Given any pre-existing XSS / HTML injection vulnerability, an attacker can bypass the Content Security Policy's _script-src_ directive by uploading a crafted attachment to any issue that, when accessed via the _file_download.php_ link, will be downloaded with a valid JavaScript MIME type resulting in script execution.\n\nThe uploaded payload must be sniffed as a valid JavaScript MIME type by PHP finfo (see file_create_finfo() API function). Non-JavaScript MIME types will not get imported in a `\u003cscript\u003e` tag by the browser, due to response header X-Content-Type-Options being set to _nosniff_, which requires all imported JavaScript files to be a valid JavaScript MIME type.\n\n### Impact\nCross-site scripting\n\n### Patches\n- 9e3bee2e7b909f4e3596985892b8bc8bee9e0bfe\n\n### Workarounds\nNone\n\n### Credits\nThanks to siunam (Tang Cheuk Hei) for discovering and responsibly reporting the issue.","status":"published","published":"2026-05-11T19:34:48Z","modified":"2026-09-10T03:51:05.076582633Z","cvss":[{"version":"4.0","score":7.6,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N","level":"high"}],"cwes":["CWE-358","CWE-79"],"updated_at":"2026-11-02T15:46:43.524801Z"}]}}