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
xenforo: xenforo
References5
- bombobombone.github.io/posts/cve-2026-73313/ ExploitThird Party Advisory
- github.com/BomboBombone/CVE-2026-73313 ExploitThird Party Advisory
- www.vulncheck.com/advisories/xenforo-mfa-bypass-via-passkey-tfa… Third Party Advisory
- xenforo.com/community/threads/security-fixes-released-for-all-x… Release Notes
- xenforo.com/community/threads/xenforo-2-3-13-and-add-ons-releas… Release Notes
Metrics
- CVSS 3.1
-
8.1
HIGH
Score source: NVD
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N - CVSS 4.0
-
7.6
HIGH
Score source: CNA
CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - EPSS — exploit probability
- 1% percentile: 48 · as of 3 November 2026
- CWE
- CWE-863
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.