CVE-2026-119561

MEDIUM 6.8

phpMyAdmin through 5.2.3 WebAuthn Two-Factor Authentication Bypass via CustomServer

CVSS Score

6.8

EPSS Score

0.0%

EPSS Percentile

0th

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.

CWE	CWE-347
Vendor	phpmyadmin
Product	phpmyadmin
Published	Oct 30, 2026

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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N

Attack Vector

Network

Attack Complexity

High

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

None

Affected Versions

phpMyAdmin / phpMyAdmin

0 ≤ 5.2.3

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: https://github.com/phpmyadmin/phpmyadmin/blob/RELEASE_5_2_3/libraries/classes/WebAuthn/CustomServer.php#L76-L110 abraxaslabs.tech: https://abraxaslabs.tech/research/PMA-5.2.3-WebAuthn-2FA abraxaslabs.tech: https://abraxaslabs.tech/research/phpmyadmin-webauthn github.com: https://github.com/phpmyadmin/phpmyadmin vulncheck.com: https://www.vulncheck.com/advisories/phpmyadmin-through-5.2.3-webauthn-two-factor-authentication-bypass-via-customserver

Credits

Abraxas Labs