CVE-2026-73319CWE-79cross-site-scripting

CVE-2026-73319

Medium · published September 8, 2026

CVSS v3.1
6.1
EPSS
0%
Percentile
34.4
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
6.1 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
CVSS v4.0
5.1 · 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
EPSS
0.00412 · 34.4th percentile
Weakness
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Published
2026-09-08T18:17Z
Affected products (1)
ProductVersionsFixed in
xenforo/xenforo< 2.3.132.3.13
References (5)
https://bombobombone.github.io/posts/cve-2026-73319/ · [email protected]https://github.com/BomboBombone/CVE-2026-73319 · [email protected]https://www.vulncheck.com/advisories/xenforo-xss-via-dynamic-redirect-handler · [email protected]https://xenforo.com/community/threads/security-fixes-released-for-all-xenforo-and-media-gallery-versions-2-2-0-2-3-12.239856/ · [email protected]https://xenforo.com/community/threads/xenforo-2-3-13-and-add-ons-released-includes-security-fixes.239857/ · [email protected]
EPSS history
Timeline
  • 10 SEP 03:18Z
    EPSS moved — → 0%
    epss
  • 08 SEP 13:19Z
    XenForo < 2.3.13 XSS via Dynamic Redirect Handler
    cvelistv5