What’s Vulnerable › Vulnerabilities

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

• Severity: high (CVSS 8.6 v4.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-05-19 · updated 2026-07-24
• Weakness: CWE-79

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 products

• mantisbt: before 2.28.2

References

• https://github.com/mantisbt/mantisbt/commit/df22697ae497ddd93f3d9132fdf4979db8d081cd
• https://github.com/mantisbt/mantisbt/security/advisories/GHSA-fvjf-68wh-rwp2
• https://mantisbt.org/bugs/view.php?id=36986

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