CVE-2025-66558
Nextcloud Twofactor WebAuthn is the WebAuthn Two-Factor Provider for Nextcloud.
Published Dec 5, 2025 · updated Oct 15, 2026 · nextcloud two-factor webauthn
Nextcloud Twofactor WebAuthn is the WebAuthn Two-Factor Provider for Nextcloud. Prior to 1.4.2 and 2.4.1, a missing ownership check allowed an attack to take-away a 2FA webauthn device when correctly guessing a 80-128 character long random string of letters, numbers and symbols. The victim would then be prompted to register a new device on the next login. The attacker can not authenticate as the victim. This vulnerability is fixed in 1.4.2 and 2.4.1.
Code
The project this record applies to. Exploit listings stay in References.
Timeline
Detection, updates, and resolution for this record.
Dec 5, 2025 · NIST NVD
Detected
Nextcloud Twofactor WebAuthn is the WebAuthn Two-Factor Provider for Nextcloud. Prior to 1.4.2 and 2.4.1, a missing ownership check allowed an attack to take-away a 2FA webauthn device when correctly guessing a 80-128 character long random string of letters, numbers and symbols. The victim would then be prompted to register a new device on the next login. The attacker can not authenticate as the v
Oct 15, 2026 · NIST NVD
Updated
Nextcloud Twofactor WebAuthn is the WebAuthn Two-Factor Provider for Nextcloud. Prior to 1.4.2 and 2.4.1, a missing ownership check allowed an attack to take-away a 2FA webauthn device when correctly guessing a 80-128 character long random string of letters, numbers and symbols. The victim would then be prompted to register a new device on the next login. The attacker can not authenticate as the v
Affected
- cpe nextcloud/two-factor webauthnversion unspecified
Sources
- CVE.orgVulnerability recordCVE-2025-66558
Official CVE identifier
cve.org - NIST NVDVulnerability recordCVE-2025-66558
Nextcloud Twofactor WebAuthn is the WebAuthn Two-Factor Provider for Nextcloud. Prior to 1.4.2 and 2.4.1, a missing ownership check allowed an attack to take-away a 2FA webauthn device when correctly guessing a 80-128 character long random string of letters, numbers and symbols.
nvd.nist.gov