A reflected XSS vulnerability in index.php in MyBB 1.8.x through 1.8.19 allows remote attackers to inject JavaScript via the 'upsetting[bburl]' parameter.
https://mybb.com/versions/1.8.20/
https://blog.mybb.com/
Source: Mitre, NVD
Published: 2019-04-11
Updated: 2026-06-17
Base Score: 4.3
Vector: CVSS2#AV:N/AC:M/Au:N/C:N/I:P/A:N
Severity: Medium
Base Score: 6.1
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
EPSS: 0.00257