CVE-2026-111911: phpMyFAQ 4.0.0 before 4.1.9 Authentication Bypass via WebAuthn Credential Injection

Is it exploited?

Not on CISA's list. CISA has not added it to the Known Exploited Vulnerabilities catalog as of 28 Oct 2026. If CISA adds it, this page shows it as known exploited.

How likely is exploitation in the next 30 days?

0.5%

EPSS score, percentile 45 of all scored records. A probability estimated by FIRST, not a report of exploitation.

CISA's SSVC assessment in the CVE record lists exploitation as poc.

How severe?

9.3 Critical

CVSS v4.0 base score, given by the CNA

What should I do?

CISA has set no required action, because the vulnerability is not in KEV.

Advisories and patches (2)

Which versions are affected?

Affected

• from 4.0.0 to before 4.1.9

Unaffected 4.1.9

Versions by product

Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of 28 Oct 2026; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of 29 Oct 2026; CVE List V5 (CVE Program), cve_2026-10-29_0000Z, as of 29 Oct 2026. About the data.

What to do

Advisories and patches

• GitHub Security Advisory (GHSA-g6cq-6rqg-6c9p) (Vendor advisory)
• GitHub Security Advisory (GHSA-rg9h-f29v-xhxr) (Vendor advisory)

Affected products and versions

As listed in the CVE record.

Versions not listed are: unaffected.

Versions the record lists as unaffected: 4.1.9.

Source: CVE List V5 (CVE Program), cve_2026-10-29_0000Z, as of 29 Oct 2026. About the data.

About this vulnerability

phpMyFAQ 4.0.0 before 4.1.9 contains an authentication bypass vulnerability where WebAuthn registration endpoints attach credentials to any account without authentication or challenge validation. Attackers can stage a victim username, submit a forged fmt=none attestation to register a passkey, then log in bypassing passwords and TOTP for account takeover.

Summary: CVE record, as of 29 Oct 2026.

• CISA has not added CVE-2026-111911 to its Known Exploited Vulnerabilities (KEV) catalog, as of 28 Oct 2026.
• The CVE record was published on 17 Oct 2026.
• The CVE record carries a CVSS v4.0 base score of 9.3 (Critical), given by its CNA.
• FIRST's EPSS model puts the probability of exploitation in the next 30 days at 0.5% (percentile 45), as of 29 Oct 2026. EPSS is a statistical estimate, not a report of exploitation.
• CISA's SSVC assessment in the CVE record: exploitation poc, automatable yes, technical impact total.

Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of 28 Oct 2026; CVE List V5 (CVE Program), cve_2026-10-29_0000Z, as of 29 Oct 2026; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of 29 Oct 2026. About the data.

Description

phpMyFAQ 4.0.0 before 4.1.9 Authentication Bypass via WebAuthn Credential Injection

phpMyFAQ 4.0.0 before 4.1.9 contains an authentication bypass vulnerability where WebAuthn registration endpoints attach credentials to any account without authentication or challenge validation. Attackers can stage a victim username, submit a forged fmt=none attestation to register a passkey, then log in bypassing passwords and TOTP for account takeover.

Source: CVE List V5 (CVE Program), cve_2026-10-29_0000Z, as of 29 Oct 2026. About the data.

Weakness

• CWE-287

CWE and CAPEC are maintained by MITRE; the entries are those named in the CVE record.

Timeline

References

• VulnCheck Advisory: phpMyFAQ 4.0.0 before 4.1.9 Authentication Bypass via WebAuthn Credential Injection (Third-party advisory)