CVE-2017-8103: In MyBB before 1.8.11, the Email MyCode component allows XSS, as demonstrated by an onmouseover event.

Security readout for executives and security teams

CVE-2017-8103 is a cross-site scripting issue in MyBB before 1.8.11. A malicious forum post or profile content using the Email MyCode component could cause script execution in another user's browser. The sources do not provide CVSS scoring or evidence of active exploitation. Exposure is most likely for internet-facing MyBB forums running versions earlier than 1.8.11, especially where untrusted users can submit content parsed by Email MyCode. Treat this as a focused web application remediation item. It is not KEV-listed in the supplied data, but public forums on old MyBB versions should be upgraded because XSS can affect users and administrators. Mitigation focus: Upgrade MyBB installations earlier than 1.8.11 to 1.8.11 or later.; Review the MyBB 1.8.11 release notes for vendor-specific security guidance.; Prioritize public forums where untrusted users can post MyCode-formatted content..

Prepared

Jun 13, 2026, 05:18 UTC (UTC+00:00)

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.