CVE-2026-73313 PUBLISHED

XenForo < 2.3.13 MFA Bypass via Passkey TFA Provider

Assigner: VulnCheck
Reserved: 11.08.2026 Published: 08.09.2026 Updated: 09.09.2026

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.

Metrics

CVSS Vector: 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
CVSS Score: 7.6

Product Status

Vendor XenForo
Product XenForo
Versions Default: unaffected
  • affected from 0 to 2.3.13 (excl.)

Credits

  • Marco Paciaroni (BomboBombone) finder
  • VulnCheck coordinator

References

Problem Types

  • Incorrect Authorization CWE