Quick answers
- Is CVE-2026-44657 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-44657 being exploited in the wild.
- How severe is CVE-2026-44657?
- High severity, with a CVSS score of 4, published 28 May 2026.
- Which products and versions are affected?
- MantisBT Mantis Bug Tracker < 2.28.2; MantisBT <= 2.28.1; mantisbt/mantisbt (Packagist) <= 2.28.1, ECOSYSTEM:introduced=0,fixed=2.28.2.
- Is there a fix for CVE-2026-44657?
- Yes. mantisbt/mantisbt (Packagist): upgrade to 2.28.2 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-44657 attacked?
- It is attacked over the network, in a web application.
- Am I affected by CVE-2026-44657?
- Check whether you run MantisBT Mantis Bug Tracker, MantisBT or mantisbt/mantisbt (Packagist) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
How to fix
- mantisbt/mantisbt (Packagist): upgrade to 2.28.2 or later
composer require mantisbt/mantisbt:^2.28.2
Technical details
A stored cross-site scripting (XSS) vulnerability exists in MantisBT's file_download.php component. By utilizing the 'show_inline=1' parameter and providing a valid 'file_show_inline_token' CSRF token, an attacker can bypass standard security controls. The exploit involves uploading a crafted XHTML attachment that references a secondary malicious JavaScript attachment. When a victim views the file inline, the script executes in their browser context. This requires low-privileged authenticated access to upload files and some user interaction to view the attachment. The issue is patched in version 2.28.2.
Affected products
- MantisBT MantisBT <= 2.28.1
Identifiers
- CVE-2026-44657
- GHSA-p6fr-rxq7-xcg8
Timeline
- 2026-05-09: disclosed
- 2026-05-11: advisory: GitHub Advisory published
- 2026-05-28: other: NVD published