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 <script> 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.
Published: 2026-05-22
Score: 7.6 High
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

Analysis and contextual insights are available on OpenCVE Cloud.

Remediation

No vendor fix or workaround currently provided.

Additional remediation guidance may be available on OpenCVE Cloud.

Tracking

Sign in to view the affected projects.

Advisories
Source ID Title
Github GHSA Github GHSA GHSA-9c3j-xm6v-j7j3 MantisBT has a Content Security Policy bypass via attachments
History

Tue, 26 May 2026 19:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Fri, 22 May 2026 21:45:00 +0000

Type Values Removed Values Added
First Time appeared Mantisbt
Mantisbt mantisbt
Vendors & Products Mantisbt
Mantisbt mantisbt

Fri, 22 May 2026 20:00:00 +0000

Type Values Removed Values Added
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 <script> 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.
Title MantisBT has a Content Security Policy bypass via attachments
Weaknesses CWE-358
CWE-79
References
Metrics cvssV4_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'}


Subscriptions

Mantisbt Mantisbt
cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-05-26T19:06:00.401Z

Reserved: 2026-04-14T14:07:59.641Z

Link: CVE-2026-40597

cve-icon Vulnrichment

Updated: 2026-05-26T19:05:57.563Z

cve-icon NVD

Status : Deferred

Published: 2026-05-22T20:16:34.347

Modified: 2026-06-17T10:45:30.607

Link: CVE-2026-40597

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-05-22T21:30:16Z

Weaknesses