---
id: CVE-2026-73310
title: >-
  XenForo before 2.3.13 contains an authorization flaw in the OAuth2 token
  endpoint that allows attackers controlling any allowlisted redirect URI to
  bypass redirect URI binding by submitting a different allowlisted URI than the
  one record…
summary: >-
  XenForo before 2.3.13 contains an authorization flaw in the OAuth2 token
  endpoint that allows attackers controlling any allowlisted redirect URI to
  bypass redirect URI binding by submitting a different allowlisted URI than the
  one record…
severity: medium
cvss: 5.9
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N'
cwe:
  - CWE-863
vendor: xenforo
product: xenforo
affected:
  - xenforo < 2.3.13
patched:
  - xenforo 2.3.13
published: '2026-09-08'
updated: '2026-09-11'
sourceUpdated: '2026-09-11T20:36:03.907'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-73310'
references:
  - url: 'https://bombobombone.github.io/posts/cve-2026-73310/'
    label: disclosure@vulncheck.com
  - url: 'https://github.com/BomboBombone/CVE-2026-73310'
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/xenforo-oauth2-authorization-code-token-theft-via-redirect-uri-bypass
    label: disclosure@vulncheck.com
  - url: >-
      https://xenforo.com/community/threads/security-fixes-released-for-all-xenforo-and-media-gallery-versions-2-2-0-2-3-12.239856/
    label: disclosure@vulncheck.com
  - url: >-
      https://xenforo.com/community/threads/xenforo-2-3-13-and-add-ons-released-includes-security-fixes.239857/
    label: disclosure@vulncheck.com
tags:
  - nvd
  - exploit-available
  - cve.org
epss: 0.00485
epssPercentile: 0.39165
exploits:
  github: 1
  githubRepos:
    - 'https://github.com/BomboBombone/CVE-2026-73310'
  checkedAt: '2026-09-26T09:05:58.805Z'
exploitAvailable: true
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-08T13:44:16.767741Z'
ingestedAt: '2026-09-08T15:33:26.984Z'
---

## Overview

XenForo before 2.3.13 contains an authorization flaw in the OAuth2 token endpoint that allows attackers controlling any allowlisted redirect URI to bypass redirect URI binding by submitting a different allowlisted URI than the one recorded at authorization time. Attackers can exchange an intercepted authorization code using a mismatched redirect URI to steal OAuth2 tokens from intercepted authorization flows.

## Affected

- `xenforo < 2.3.13`

## Remediation

Upgrade past the affected range:

- `xenforo 2.3.13`