Vulnerability · Published Sep 8, 2026 · Assigned by VulnCheck

CVE-2026-73313XenForo < 2.3.13 MFA Bypass via Passkey TFA Provider

Medium 6.8

In plain English

A medium-severity incorrect authorization in XenForo from XenForo. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 48% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code.

Severity (CVSS 3.1)6.8Medium

Exploit odds (30 days)0.6%top 52.2% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack tooling1Public PoC

Official description

XenForo before 2.3.13 contains a multi-factor authentication bypass vulnerability in the passkey TFA provider that allows an authenticated attacker to complete login as another user by submitting their own registered passkey credential during the WebAuthn assertion step. The passkey verification path performs a global credential lookup without validating that the matched credential belongs to the user whose login is pending, enabling an attacker who knows a target account's password to sign the challenge with their own passkey and bypass multi-factor authentication on both public forum and ACP login paths.

Affected products (as reported)

Vendor	Product	Versions
XenForo	XenForo	0 – before 2.3.13

Weakness: CWE-863 · Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N

References

Vendor Advisory vendor-advisory, patch
Release Notes release-notes
Researcher Advisory technical-description
Researcher PoC exploit
https://www.vulncheck.com/advisories/xenforo-mfa-bypass-via-passkey-tfa-provider third-party-advisory