CVE-2026-40596
MantisBT is Vulnerable to XSS leading to account takeover via updating a user's font family preference
Description
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](https://github.com/mantisbt/mantisbt/security/advisories/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.
How to fix CVE-2026-40596
To remediate CVE-2026-40596, upgrade the affected package to a fixed version below.
- —upgrade to 2.28.2 or later
Is CVE-2026-40596 being exploited?
Low — EPSS is 0.1%, meaning exploitation activity has not been observed at scale.
Affected packages (1)
- >= 2.11.0, < 2.28.2
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 4.0 | — | 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 |