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TI-2026-22187 Aliases CVE-2026-27836GHSA-w22q-m2fm-x9f4

phpMyFAQ Allows Unauthenticated Account Creation via WebAuthn Prepare Endpoint

Priority HIGH 72CWE-862Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Security bypass
Confidentiality · integrity · availability
None · High · None
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-862.

Summary

phpMyFAQ is an open source FAQ web application. Prior to version 4.0.18, the WebAuthn prepare endpoint (`/api/webauthn/prepare`) creates new active user accounts without any authentication, CSRF protection, captcha, or configuration checks. This allows unauthenticated attackers to create unlimited user accounts even when registration is disabled. Version 4.0.18 fixes the issue.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00452 39th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed phpMyFAQ (thorsten): 4.0.18thorsten/phpmyfaq (Packagist): 4.0.18

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
thorstenphpMyFAQbefore 4.0.184.0.18Patch availableCNA
—thorsten/phpmyfaq (Packagist)before 4.0.184.0.18Patch availableGHSA-w22q-m2fm-x9f4
  • phpMyFAQ Vendorthorsten Affected before 4.0.18 Fixed in 4.0.18 Patch available CNA
  • thorsten/phpmyfaq (Packagist) Vendor— Affected before 4.0.18 Fixed in 4.0.18 Patch available GHSA-w22q-m2fm-x9f4

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:phpmyfaq:phpmyfaq:*:*:*:*:*:*:*:*before 4.0.18Vulnerablethorsten
  • cpe:2.3:a:phpmyfaq:phpmyfaq:*:*:*:*:*:*:*:* Versions before 4.0.18 Vulnerable ·thorsten

Remediation

  • Fix · CNA phpMyFAQ (thorsten) Fixed in 4.0.18
  • Fix · GHSA-w22q-m2fm-x9f4 thorsten/phpmyfaq (Packagist) Fixed in 4.0.18 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-27836
  2. 2026-10-03 Alias added: GHSA-w22q-m2fm-x9f4

References

Exploit 1

Patch 1

Advisory 1

Other 1

  • TI-2023-00296 Improper Authentication in thorsten/phpmyfaq CVSS 3.1CRITICAL 9.8
  • TI-2026-53313 phpMyFAQ 3.1.0 through 4.1.6 Authentication Bypass via LDAP CVSS 4.0HIGH 8.8
  • TI-2025-37331 phpMyFAQ duplicate email registration allows multiple accounts with the same email CVSS 3.1CRITICAL 9.8
  • TI-2024-36257 phpMyFAQ Generates an Error Message Containing Sensitive Information if database server is not available CVSS 3.1HIGH 8.6
  • TI-2023-03720 Improper Neutralization of Formula Elements in a CSV File in thorsten/phpmyfaq CVSS 3.1CRITICAL 9.8
  • TI-2023-00749 Command Injection in thorsten/phpmyfaq CVSS 3.1CRITICAL 9.8
See all 153 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences