CVE-2026-39960

MEDIUM EPSS 13.7%
Published May 20, 20261mo ago · Modified Jun 17, 20262w ago
5.4 CVSS 3.1
Medium
Find Similar
Published May 20, 2026 1mo ago
Last Modified Jun 17, 2026 2w ago

Description

Mantis Bug Tracker (MantisBT) is an open source issue tracker. Versions 2.28.1 and below contain flawed logic that causes improper escaping of a textarea custom field's contents in the Update Issue page, (bug_update_page.php) allowing an attacker to inject HTML and, if CSP settings permit, execute arbitrary JavaScript when the page is loaded. This facilitates session theft, leading to admin account takeover, full project data access. In order to exploit this issue, a textarea-type custom field must be configured for the project, the attack must be carried out by an authenticated user with bug report permission (low privilege). This can affect any user viewing the bug edit form, including administrators. The issue has been fixed in version 2.28.2. If users cannot immediately upgrade, they can work around the issue by using the default Content-Security Policy, which blocks script execution.

CVSS Details

Base Score
5.4
Exploitability
2.3
Impact
2.7
Vector string
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
Attack Vector Network
Attack Complexity Low
Privileges Required Low
User Interaction Required
Scope Changed
Confidentiality Low
Integrity Low
Availability None

Threat Intelligence

EPSS Exploit Probability
13.7% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available

Weaknesses 1

CWE-79 Cross-site Scripting Injection

References 2

  • github.com https://github.com/mantisbt/mantisbt/commit/5fec0f448b7a7d7d539a6adb6dccceac4e4e4ab7
  • github.com https://github.com/mantisbt/mantisbt/security/advisories/GHSA-qj6w-v29q-4rgx

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.