phpMyAdmin through 5.2.3 contains an authentication bypass vulnerability in CustomServer::parseAndValidateAssertionResponse() that never verifies WebAuthn assertion signatures against stored public keys
Affects phpmyadminSource GCVE Database
Not known to be exploited · CVSS 7.6 High.
Data as of 5 Nov 2026, 12:35 UTC
Thin evidence
One scorer or none| CNA (VulnCheck) | CVSS 4.0 | 7.6 |
|---|---|---|
| CNA (VulnCheck) | CVSS 3.1 | 6.8 |
| CNA | CVSS 4.0 | 7.6 |
CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 30 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 5 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.10phpmyadminpkg:deb/ubuntu/phpmyadmin?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSphpmyadminpkg:deb/ubuntu/phpmyadmin?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSphpmyadminpkg:deb/ubuntu/phpmyadmin?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 22.04 LTSphpmyadminpkg:deb/ubuntu/phpmyadmin?arch=source&distro=jammyOther threats | Affected
| Fixed in– |
Ubuntu Pro 20.04 LTSphpmyadminpkg:deb/ubuntu/phpmyadmin?arch=source&distro=esm-apps/focalOther threats | Affected
| Fixed in– |
Ubuntu Pro 18.04 LTSphpmyadminpkg:deb/ubuntu/phpmyadmin?arch=source&distro=esm-apps/bionicOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
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
- ubuntu.com/security/CVE-2026-119561 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-119561 (opens in a new tab)
- abraxaslabs.tech/research/PMA-5.2.3-WebAuthn-2FA (opens in a new tab)
- abraxaslabs.tech/research/phpmyadmin-webauthn (opens in a new tab)
- github.com/phpmyadmin/phpmyadmin (opens in a new tab)
- github.com/phpmyadmin/phpmyadmin/blob/RELEASE_5_2_3/libraries/classes/WebAuthn/CustomServer.php (opens in a new tab)
- vulncheck.com/advisories/phpmyadmin-through-5.2.3-webauthn-two-factor-authentication-bypass-via-customserver (opens in a new tab)