CVE-2026-73311CWE-294

CVE-2026-73311

High · published September 8, 2026

CVSS v3.1
7.4
EPSS
0%
Percentile
41.8
In the wild
Unconfirmed
What it is

XenForo before 2.3.13 contains an OAuth2 authorization code reuse vulnerability that allows attackers to obtain unauthorized token pairs by submitting a previously used authorization code. Attackers can exploit the failure to invalidate or mark authorization codes as consumed after initial token issuance to receive an independent token pair for the same user and scopes, bypassing the single-use guarantee of the OAuth2 authorization code flow.

The record
Technical detail
CVSS v3.1
7.4 · HIGH
Vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
CVSS v4.0
9.1 · CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
EPSS
0.00498 · 41.8th percentile
Weakness
CWE-294 · Authentication Bypass by Capture-replay
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-2026-73311/ · [email protected]https://github.com/BomboBombone/CVE-2026-73311 · [email protected]https://www.vulncheck.com/advisories/xenforo-oauth2-authorization-code-reuse · [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 13:16Z
    XenForo < 2.3.13 OAuth2 Authorization Code Reuse
    cvelistv5