CVE-2026-73313
highpriority · track · 42OT risk · elevatedEPSS 0.006 · 48 %ileexploit · PoCUSEPSS · scored 2026-10-28
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.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6.7–8.1
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
exploits (1)
Public proof-of-concept and weaponised exploit code.
affected products (1)
Products and version ranges known to be affected.
sources
Which sources assert this record, and when.
references (5) nvd
External citations — patches, advisories, analysis.
- https://bombobombone.github.io/posts/cve-2026-73313/ExploitThird Party Advisory
- https://github.com/BomboBombone/CVE-2026-73313ExploitThird Party Advisory
- https://www.vulncheck.com/advisories/xenforo-mfa-bypass-via-passkey-tfa-providerThird Party Advisory
- https://xenforo.com/community/threads/security-fixes-released-for-all-xenforo-and-media-gallery-versions-2-2-0-2-3-12.239856/Release Notes
- https://xenforo.com/community/threads/xenforo-2-3-13-and-add-ons-released-includes-security-fixes.239857/Release Notes
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