Which versions of Xenforo are affected by EUVD-2025-209152?

XenForo versions before 2.3.7 contain a critical authentication bypass in passkey-based login that allows unauthenticated remote attackers to gain unauthorized account access.. A patch is available.

How to fix or mitigate EUVD-2025-209152?

Within 24 hours: Identify all XenForo instances in use and confirm current version numbers. Within 7 days: Upgrade all XenForo installations to version 2.3.7 or later and apply vendor-released patch. Within 30 days: Audit passkey-enabled accounts for unauthorized access activity and reset credentials for any suspicious logins; review access logs for authentication anomalies during the vulnerability window.

Xenforo EUVD-2025-209152

Q: What is the CVSS score of EUVD-2025-209152?

EUVD-2025-209152 has a CVSS 4.0 base score of 9.3 (Critical). CVSS vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/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 exploitation probability: 0.1%.

| CVE-2025-71279 CRITICAL

Improper Authentication (CWE-287)

2026-04-01 VulnCheck

GHSA-gqgm-83rg-vhcj

Authentication Bypass Xenforo

9.3

CVSS 4.0 · NVD

Severity by source

NVD PRIMARY

9.3 CRITICAL

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/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

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/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

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Lifecycle Timeline

Analysis Updated

Apr 16, 2026 - 05:47 EUVD-patch-fix

executive_summary

Re-analysis Queued

Apr 16, 2026 - 05:29 backfill_euvd_patch

patch_released

Patch available

Apr 16, 2026 - 05:29 EUVD

2.3.7

EUVD ID Assigned

Apr 01, 2026 - 01:15 euvd

EUVD-2025-209152

Analysis Generated

Apr 01, 2026 - 01:15 vuln.today

CVE Published

Apr 01, 2026 - 00:30 nvd

CRITICAL 9.3

DescriptionCVE.org

XenForo before 2.3.7 contains a security issue affecting Passkeys that have been added to user accounts. An attacker may be able to compromise the security of Passkey-based authentication.

AnalysisAI

Authentication bypass in XenForo versions prior to 2.3.7 compromises passkey-based authentication, allowing remote unauthenticated attackers to bypass security controls protecting passkey-enabled user accounts. No public exploit identified at time of analysis, though EPSS data not available. The vulnerability affects a critical authentication mechanism (WebAuthn/passkeys), representing a high-severity threat to forum platforms relying on this modern authentication method.

Technical ContextAI

XenForo is a commercial forum software platform that implemented passkey support for WebAuthn-based passwordless authentication. This vulnerability is classified as CWE-287 (Improper Authentication), indicating a fundamental flaw in how the platform validates passkey authentication attempts. Passkeys leverage public key cryptography where the private key remains on the user's device and the public key is stored server-side. The vulnerability suggests improper validation of the authentication ceremony, signature verification, or challenge-response mechanism, potentially allowing attackers to authenticate as passkey-enabled users without possessing the legitimate credential. The affected product is identified by CPE cpe:2.3:a:xenforo:xenforo:*:*:*:*:*:*:*:*, indicating all XenForo versions prior to the patched release are vulnerable.

RemediationAI

Vendor-released patch: XenForo 2.3.7. Administrators should immediately upgrade all XenForo installations to version 2.3.7 or later, which includes security fixes addressing the passkey authentication bypass. The official vendor advisory with upgrade instructions is available at https://xenforo.com/community/threads/xenforo-2-3-7-released-includes-security-fixes.232121/. As an interim measure if immediate patching is not feasible, administrators may consider temporarily disabling passkey authentication functionality until the upgrade can be completed, though this should be balanced against user experience impacts. Review authentication logs for any suspicious passkey authentication attempts prior to patching, particularly successful logins for passkey-enabled accounts during unusual timeframes or from unexpected locations.