MantisBT is Vulnerable to XSS leading to account takeover via updating a user's font family preference
Any authenticated user can inject arbitrary HTML via updating their account's font family.
Impact
Cross-site scripting. The injected payload will be reflected in every MantisBT page.
Leveraging another vulnerability (CSP bypass, see GHSA-9c3j-xm6v-j7j3), the attacker could achieve account takeover.
Patches
- 9e8409cdd979eba86ef532756fc47c1d8112d22d
Workarounds
None
Credits
Thanks to siunam (Tang Cheuk Hei) for discovering and responsibly reporting the issue.
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Composer package | mantisbt/mantisbt | >= 2.11.0, < 2.28.2 | 2.28.2 |
References
- https://github.com/mantisbt/mantisbt/security/advisories/GHSA-9c3j-xm6v-j7j3
- https://github.com/mantisbt/mantisbt/security/advisories/GHSA-j3v9-553h-x28j
- https://nvd.nist.gov/vuln/detail/CVE-2026-40596
- https://github.com/mantisbt/mantisbt/commit/9e8409cdd979eba86ef532756fc47c1d8112d22d
- https://github.com/mantisbt/mantisbt
- https://mantisbt.org/bugs/view.php?id=37011
- https://mantisbt.org/bugs/view.php?id=37016
- CVSS vector
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:H/VI:L/VA:L/SC:H/SI:H/SA:L- Weakness (CWE)
CWE-79- Platform
- Composer
- Package
mantisbt/mantisbt- Disclosed
- 11.05.2026
- Updated
- 11.10.2026 10:22
Sources and licenses
OSV / GitHub Advisory Database - GHSA-j3v9-553h-x28j - CC BY 4.0
Vulnerability history: mantisbt/mantisbt
All published vulnerabilities of this package (Composer package), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 74
- First → latest
- 04.2022 07.2026
- Without a fix
- 2
- Exploited in attacks
- 0
Severity breakdown
- Critical 4
- High 20
- Medium 49
- Low 1
Disclosures per year
- 2022: 34
- 2023: 2
- 2024: 5
- 2025: 4
- 2026: 29
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MantisBT is Vulnerable to XSS leading to account takeover via updating a user's font family preference this entry
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