by Kastro
Paper/Archive/CVE-2026-76214

CVE-2026-76214

thorsten phpMyFAQ — phpMyFAQ before 4.1.7 WebAuthn Replay Attack via Challenge

EPSS 0.4%CVSS 9.1
critical.is priorityof 100
34
CVSS 9.1 (CNA)9.1 / 10 × 3027.3Not in CISA KEV+300.0EPSS percentile 33.3.333 × 206.7No public exploit+100.0SSVC exploitation: none+100.0
Description · from the CVE record

phpMyFAQ before 4.1.7 fails to persist the WebAuthn login challenge generated by prepareForLogin, because neither WebAuthn controller saves the mutated key objects back to the database. At login the anti-replay comparison is skipped by its own null guard, allowing an attacker who captures a successful WebAuthn assertion to replay it indefinitely and authenticate as the user without any interaction or hardware key.

Affected

ProductAffectedFixed inSource
phpMyFAQ< 4.1.74.1.7CNA

Scores by source

VulnCheck (CNA)9.1CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
VulnCheck (CNA)7.4CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
CISA ADPSSVCExploitation: none · Automatable: no · Technical impact: partial

References

advisorygithub.com/thorsten/phpMyFAQ/security/advisories/GHSA-f534-wv9g-wx2wwriteupvulncheck.com/advisories/phpmyfaq-before-webauthn-replay-attack-via-challenge