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.
Fix
Patch, vendor advisory and mitigation references on NVD 4
- https://github.com/nextcloud/security-advisories/security/advisories/GHSA-fr8x-mvjg-wf9q Patch, Vendor Advisory
- https://github.com/nextcloud/twofactor_webauthn/commit/5d2302166d31ee2e01b2e21556bd5372156da13d Patch
- https://github.com/nextcloud/twofactor_webauthn/pull/881 Issue Tracking, Patch
- https://hackerone.com/reports/3360354 Permissions Required, Vendor Advisory
Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.
Change history 1
- First seenCVSS 4.3 · nextcloudNVD modified 2026-10-15 21:10
Affected (CPE criteria) 1
cpe:2.3:a:nextcloud:two-factor_webauthn:*:*:*:*:*:*:*:*
References 4
- https://github.com/nextcloud/security-advisories/security/advisories/GHSA-fr8x-mvjg-wf9q Patch, Vendor Advisory
- https://github.com/nextcloud/twofactor_webauthn/commit/5d2302166d31ee2e01b2e21556bd5372156da13d Patch
- https://github.com/nextcloud/twofactor_webauthn/pull/881 Issue Tracking, Patch
- https://hackerone.com/reports/3360354 Permissions Required, Vendor Advisory