CVE-2026-119561
phpMyAdmin through 5.2.3 WebAuthn Two-Factor Authentication Bypass via CustomServer
- State
- Published
- Severity
- 7.6 High
- Published
- Oct 30, 2026
- Updated
- Oct 30, 2026
- Reserved
- Oct 30, 2026
Description
phpMyAdmin through 5.2.3 contains an authentication bypass vulnerability in CustomServer::parseAndValidateAssertionResponse() that never verifies WebAuthn assertion signatures against stored public keys. Attackers holding a victim's MySQL credentials can POST a crafted webauthn_request_response with matching challenge, origin, and rpIdHash to bypass the second factor and gain database privileges.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 7.6 High | CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N | VulnCheck |
| 3.1 | 6.8 Medium | CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N | VulnCheck |
Weaknesses
- CWE-347 Improper Verification of Cryptographic Signature
Affected Products
| Product | Versions |
|---|---|
phpMyAdminphpMyAdmin |
|
References
- https://github.com/phpmyadmin/phpmyadmin/blob/RELEASE_5_2_3/libraries/classes/WebAuthn/CustomServer.php#L76-L110technical-description
- https://abraxaslabs.tech/research/PMA-5.2.3-WebAuthn-2FAthird-party-advisory
- https://abraxaslabs.tech/research/phpmyadmin-webauthnthird-party-advisory
- https://github.com/phpmyadmin/phpmyadminproduct
- VulnCheck Advisory: phpMyAdmin through 5.2.3 WebAuthn Two-Factor Authentication Bypass via CustomServerthird-party-advisory
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