CVE-2026-52881: MantisBT: Reflected XSS in admin/install.php via unescaped printf

July 15, 2026

MantisBT 2.28.3 and earlier contains six reflected XSS injection points in /admin/install.php. User-supplied parameters are echoed into HTML without escaping via an unescaped printf format string. No authentication is required.

A Content Security Policy (script-src ‘self’) prevents inline JavaScript execution, but the CSP is missing a form-action directive, allowing exploitation via credential-phishing form injection and open redirects.

References

github.com/advisories/GHSA-vcrw-4xvv-jh49
github.com/mantisbt/mantisbt/commit/297773fbb238c39a153bd888431b41a176132098
github.com/mantisbt/mantisbt/security/advisories/GHSA-vcrw-4xvv-jh49
mantisbt.org/bugs/view.php?id=37103
nvd.nist.gov/vuln/detail/CVE-2026-52881

Code Behaviors & Features

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