CVE-2026-119561

high

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.

References

https://www.vulncheck.com/advisories/phpmyadmin-through-5.2.3-webauthn-two-factor-authentication-bypass-via-customserver

https://github.com/phpmyadmin/phpmyadmin/blob/RELEASE_5_2_3/libraries/classes/WebAuthn/CustomServer.php#L76-L110

https://github.com/phpmyadmin/phpmyadmin

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-113826

https://abraxaslabs.tech/research/phpmyadmin-webauthn

https://abraxaslabs.tech/research/PMA-5.2.3-WebAuthn-2FA

Details

Source: Mitre, NVD

Published: 2026-10-30

Updated: 2026-10-30

Risk Information

CVSS v2

Base Score: 6.6

Vector: CVSS2#AV:N/AC:H/Au:S/C:C/I:C/A:N

Severity: Medium

CVSS v3

Base Score: 6.8

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

Severity: Medium

CVSS v4

Base Score: 7.6

Vector: 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

Severity: High

EPSS

EPSS: 0.00186