The installer in MyBB before 1.8.13 has XSS.
https://blog.mybb.com/2017/11/07/mybb-1-8-13-released-security-maintenance-release/
Source: Mitre, NVD
Published: 2017-11-10
Updated: 2026-06-17
Base Score: 3.5
Vector: CVSS2#AV:N/AC:M/Au:S/C:N/I:P/A:N
Severity: Low
Base Score: 5.4
Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
Severity: Medium
EPSS: 0.0027