CVE-2026-73319
XenForo before 2.3.13 contains a cross-site scripting vulnerability in the dynamic redirect handler that allows unauthenticated attackers to execute arbitrary JavaScript in the board origin by crafting a malicious javascript: URI that bypasses host validation. Attackers can embed the board hostname in the URI authority component and use percent-encoded newlines to evade server-side filters, causing authenticated users who perform a Follow action to execute attacker-supplied JavaScript in their browser.
- Published Sep 8, 2026
- CVSS 5.1 medium
- 0.4% chance of exploitation in the next 30 days (EPSS)
- Public exploit code is available
- A fix is available