CVE-2026-73313
XenForo < 2.3.13 MFA Bypass via Passkey TFA Provider
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.
INFO
Published Date :
Sept. 8, 2026, 2:17 p.m.
Last Modified :
Sept. 14, 2026, 8:16 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | MEDIUM | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 3.1 | MEDIUM | [email protected] | ||||
| CVSS 3.1 | HIGH | [email protected] | ||||
| CVSS 4.0 | HIGH | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 4.0 | HIGH | [email protected] |
Solution
- Update XenForo to 2.3.13 or later.
- Verify passkey TFA provider configuration.
- Monitor authentication logs for suspicious activity.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-73313.
| URL | Resource |
|---|---|
| https://bombobombone.github.io/posts/cve-2026-73313/ | Exploit Third Party Advisory |
| https://github.com/BomboBombone/CVE-2026-73313 | Exploit Third Party Advisory |
| https://www.vulncheck.com/advisories/xenforo-mfa-bypass-via-passkey-tfa-provider | Third 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 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-73313 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-73313
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-73313 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-73313 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Sep. 14, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-73313', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-09-14T19:22:47.378555Z'} -
Initial Analysis by [email protected]
Sep. 11, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N Added CPE Configuration OR *cpe:2.3:a:xenforo:xenforo:*:*:*:*:*:*:*:* versions up to (excluding) 2.3.13 Added Reference Type VulnCheck: https://bombobombone.github.io/posts/cve-2026-73313/ Types: Exploit, Third Party Advisory Added Reference Type VulnCheck: https://github.com/BomboBombone/CVE-2026-73313 Types: Exploit, Third Party Advisory Added Reference Type VulnCheck: https://www.vulncheck.com/advisories/xenforo-mfa-bypass-via-passkey-tfa-provider Types: Third Party Advisory Added Reference Type VulnCheck: https://xenforo.com/community/threads/security-fixes-released-for-all-xenforo-and-media-gallery-versions-2-2-0-2-3-12.239856/ Types: Release Notes Added Reference Type VulnCheck: https://xenforo.com/community/threads/xenforo-2-3-13-and-add-ons-released-includes-security-fixes.239857/ Types: Release Notes -
CVE Modified by [email protected]
Sep. 09, 2026
Action Type Old Value New Value Added Reference https://bombobombone.github.io/posts/cve-2026-73313/ Added Reference https://github.com/BomboBombone/CVE-2026-73313 -
New CVE Received by [email protected]
Sep. 08, 2026
Action Type Old Value New Value Added 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. Added CVSS V4.0 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 Added CVSS V3.1 AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N Added CWE CWE-863 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/73xxx/CVE-2026-73313.json">CVE-2026-73313</a> Added Reference https://www.vulncheck.com/advisories/xenforo-mfa-bypass-via-passkey-tfa-provider Added Reference https://xenforo.com/community/threads/security-fixes-released-for-all-xenforo-and-media-gallery-versions-2-2-0-2-3-12.239856/ Added Reference https://xenforo.com/community/threads/xenforo-2-3-13-and-add-ons-released-includes-security-fixes.239857/