Critical

Passkey Authentication Security Bypass in XenForo before 2.3.7

IdentifiersCVE-2025-71279CWE-287· Improper Authentication

CVE-2025-71279 is a security issue in XenForo versions prior to 2.3.7 affecting Passkeys that have been added to user accounts. The available information indicates that the flaw can compromise the security of passkey-based authentication, implying that the authentication mechanism for registered passkeys does not correctly enforce or validate authentication requirements in some circumstances. Publicly provided details are limited, and no specific vulnerable function or code path is identified in the supplied content. The issue is classified as CWE-287, indicating improper authentication.

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ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

Successful exploitation may allow an attacker to compromise passkey-based authentication for affected XenForo accounts. Given the supplied CVSS assessment and description, the likely impact includes unauthorized account access and the ability to act as the affected user. Depending on the privileges of the compromised account, this could expose sensitive forum data, permit unauthorized administrative or moderation actions, alter content or configuration, and potentially disrupt service integrity and availability.

Mitigation

If you can’t patch tonight, do this now.

If immediate patching is not possible, reduce exposure by disabling Passkey-based authentication until the update can be applied, especially for privileged accounts. Require alternative MFA methods for administrator and moderator accounts, monitor authentication logs for anomalous passkey-related logins, and review account activity for signs of unauthorized access. Because the available information does not provide a vendor-endorsed workaround, mitigation should be treated as temporary and incomplete pending upgrade to 2.3.7 or later.

Remediation

Patch, then assume compromise.

Upgrade XenForo to version 2.3.7 or later, as XenForo 2.3.7 is identified as including the security fixes for this issue. Apply the vendor-provided update across all affected installations and ensure that all application files and related components are fully updated. After patching, review accounts using Passkeys and consider revalidating or re-enrolling passkeys for sensitive or administrative accounts if recommended by the vendor or internal policy.

PUBLIC EXPLOITS

Exploits

No public exploits tracked yet. Mallory keeps watching.

VALID 0 / 0 TOTALView more in app

No public exploit code observed for this vulnerability.

EXPOSURE SURFACE

Affected products & vendors

Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.

VendorProductType

XenforoXenforoapplication

Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.

ACTIVITY FEED

Recent activity

4 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.

4 SOURCESView more in app

cvefeed high severityNews

Apr 1, 2026

CVE-2025-71279 - XenForo Passkey Security Bypass

A vulnerability in XenForo before 2.3.7 affecting passkey-based authentication that may allow an attacker to compromise the security of passkeys added to user accounts.

What this page doesn’t show

The version that knows your environment.

This page is what’s public. Mallory adds the parts that aren’t: which of your assets are affected, which adversaries are exploiting it right now, which detections to deploy, and what to do tonight.

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Exposure mapping

Query your assets running an affected version, and investigate the blast radius.

Threat actor evidence

Every observed campaign linking this CVE to a named adversary.

Associated malware

Malware families riding this exploit, with evidence and IOCs.

Detection signatures

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

Vendor-by-vendor mapping

Cross-references every affected SKU, including bundled OEM variants.

Social activity3