CVE-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…

PriorityP420medium4.3CVSS 3.1

AVNACLPRNUIRSUCNILAN

EPSS

0.23%

13.3th percentile

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.

Affected

4 ranges

Vendor	Product	Version range	Fixed in
nextcloud	security-advisories	< 1.4.2	1.4.2
nextcloud	security-advisories	—	—
nextcloud	two-factor_webauthn	>= 1.0.0 < 1.4.2	1.4.2
nextcloud	two-factor_webauthn	>= 2.0.0 < 2.4.1	2.4.1

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