Vulnerability · Published Sep 8, 2026 · Assigned by VulnCheck

CVE-2026-73319XenForo < 2.3.13 XSS via Dynamic Redirect Handler

Medium 6.1

In plain English

A medium-severity cross-site scripting in XenForo from XenForo. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 36% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code.

Severity (CVSS 3.1)6.1Medium

Exploit odds (30 days)0.4%top 64.3% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack tooling1Public PoC

Official description

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.

Affected products (as reported)

Vendor	Product	Versions
XenForo	XenForo	0 – before 2.3.13

Weakness: CWE-79 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

References

Vendor Advisory vendor-advisory, patch
Release Notes release-notes
Researcher Advisory technical-description
Researcher PoC exploit
https://www.vulncheck.com/advisories/xenforo-xss-via-dynamic-redirect-handler third-party-advisory