mantisbt Mantis Bug Tracker up to 2.28.1 Attachment file_create_finfo cross site scripting

Summaryinfo

A vulnerability, which was classified as problematic, has been found in mantisbt Mantis Bug Tracker up to 2.28.1. This impacts the function file_create_finfo of the component Attachment Handler. This manipulation causes cross site scripting. This vulnerability is registered as CVE-2026-40597. Remote exploitation of the attack is possible. No exploit is available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability classified as problematic was found in mantisbt Mantis Bug Tracker up to 2.28.1. Affected by this vulnerability is the function file_create_finfo of the component Attachment Handler. The manipulation with an unknown input leads to a cross site scripting vulnerability. The CWE definition for the vulnerability is CWE-79. The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. As an impact it is known to affect integrity. The summary by CVE is:

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 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.

It is possible to read the advisory at github.com. This vulnerability is known as CVE-2026-40597 since 04/14/2026. The exploitation appears to be easy. The attack can be launched remotely. It demands that the victim is doing some kind of user interaction. Technical details of the vulnerability are known, but there is no available exploit. The attack technique deployed by this issue is T1059.007 according to MITRE ATT&CK.

Upgrading to version 2.28.2 eliminates this vulnerability. Applying the patch 9e3bee2e7b909f4e3596985892b8bc8bee9e0bfe is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

Type

• Bug Tracking Software

Vendor

• mantisbt

Name

• Mantis Bug Tracker

Version

• 2.28.0
• 2.28.1

License

• open-source

CPE 2.3info

• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒

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