High 7.4Published Sep 8, 2026

CVE-2026-73311XenForo < 2.3.13 OAuth2 Authorization Code Reuse

Updated under an hour ago (2026-10-19 06:30 UTC)

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No exploitation reported and no EPSS estimate yet.

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Exploited in the last 30 days

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.

CVSS: 7.4 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
Weakness (CWE): CWE-294
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: VulnCheck
NVD analysis: Analyzed
Record last updated: Oct 1, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

XenForo XenForo xenforo:xenforo (from the name)	before 2.3.13	CNA record
xenforo xenforo xenforo:xenforo	before 2.3.13	NVD

References

https://xenforo.com/community/threads/security-fixes-released-for-all-xenforo-and-media-gallery-versions-2-2-0-2-3-12.239856/vendor-advisory, patch, release-notes
https://xenforo.com/community/threads/xenforo-2-3-13-and-add-ons-released-includes-security-fixes.239857/release-notes
https://bombobombone.github.io/posts/cve-2026-73311/technical-description, exploit, third-party-advisory
https://github.com/BomboBombone/CVE-2026-73311exploit, third-party-advisory
https://www.vulncheck.com/advisories/xenforo-oauth2-authorization-code-reusethird-party-advisory

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.