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Vulnerability · Published May 19, 2026 · Assigned by GitHub_M

CVE-2026-34463MantisBT has Stored HTML Injection/XSS via Clone Issue Form

High 8.6

In plain English

A high-severity cross-site scripting in mantisbt from mantisbt. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 39% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 4.0)8.6High
Exploit odds (30 days)0.4%top 61.2% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

Mantis Bug Tracker (MantisBT) is an open source issue tracker. Versions 2.28.1 and prior contain a Stored XSS vulnerability. When cloning an issue originating from a Project other than the current one, the clone form (bug_report_page.php) prepends the source Project name before the category selector without proper escaping, allowing an attacker able to to inject HTML if they can set the Project's name (which typically requires manager or administrator access level). This issue has been resolved in version 2.28.2.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Packagistmantisbt/mantisbt2.28.2GHSA-fvjf-68wh-rwp2

Affected products (as reported)

VendorProductVersions
mantisbt mantisbt < 2.28.2

Weakness: CWE-79 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

References