# CVE-2026-73319

## Summary

- **CVE ID:** CVE-2026-73319
- **Severity:** MEDIUM
- **CVSS Score:** 6.1 (CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N)
- **CWE:** CWE-79
- **Published:** Sep 8, 2026
- **Last Modified:** Sep 9, 2026

## 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

- XenForo — XenForo (0)

## References

- [CNA](https://xenforo.com/community/threads/security-fixes-released-for-all-xenforo-and-media-gallery-versions-2-2-0-2-3-12.239856/)
- [CNA](https://xenforo.com/community/threads/xenforo-2-3-13-and-add-ons-released-includes-security-fixes.239857/)
- [CNA](https://www.vulncheck.com/advisories/xenforo-xss-via-dynamic-redirect-handler)
- [CNA](https://bombobombone.github.io/posts/cve-2026-73319/)
- [CNA](https://github.com/BomboBombone/CVE-2026-73319)

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-09._