CVE-2026-73311criticalCWE-294

CVE-2026-73311: critical vulnerability in XenForo

XenForo < 2.3.13 OAuth2 Authorization Code Reuse

Published · Updated

Follow this CVE+ Monitor XenForo

E-mail alert when it lands in KEV, gets a public PoC or its score goes up.

48Vexday Risk Score

No sign of exploitation. It has a public proof of concept.

ssvc Attendcvss 9.1epss 0.5%
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:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
Affected products
XenForo · XenForo
⚠ Public resources, to assess the exposure of systems you control or are authorized to test. Test only with authorization.
Related CVEs — XenForo

In the same product, most dangerous first.

CVE-2026-74239HIGHXenForo < 2.3.13 Path Traversal via Style Archive Importer on WindowsEPSS 0.9%CVE-2026-73309CRITICALXenForo < 2.3.13 Authentication Bypass via OAuth2 Token EndpointEPSS 0.7%CVE-2026-35056HIGHXenForo Remote Code Execution via Authenticated AdminEPSS 0.7%CVE-2026-73314HIGHXenForo < 2.3.13 Signature Verification Bypass via PayPal REST WebhookEPSS 0.7%CVE-2026-73321HIGHXenForo < 2.3.13 Uncontrolled Recursion DoS via BBCode ParserEPSS 0.6%CVE-2026-73313HIGHXenForo < 2.3.13 MFA Bypass via Passkey TFA ProviderEPSS 0.6%