CVE-2026-40596

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.