CVE-2026-76214
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.29%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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.
- CVSS 4.0
- 9.1 CRITICALCVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.29% probability · 22th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-294
- Affected
- phpmyfaq/phpmyfaq
- Source
- disclosure@vulncheck.com
References
- https://github.com/thorsten/phpMyFAQ/security/advisories/GHSA-f534-wv9g-wx2wMitigation, Vendor Advisory
- https://www.vulncheck.com/advisories/phpmyfaq-before-webauthn-replay-attack-via-challengeThird Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.