🛡️ CVE-2025-66558 — two-factor-webauthn

🟢 CVSS 3.1 — Low ✅ No Known Exploit CWE-639 NVD
3.1
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

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.

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is high, an attacker needs low-level privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality none, integrity low, availability none.

Weakness class

CVE-2025-66558 is classified as CWE-639: Authorization Bypass Through User-Controlled Key. An object is selected by an identifier from the request without checking the caller owns it.

Affected software

CVE-2025-66558 is recorded against 1 package.

  • two-factor-webauthn (from 2.0.0 up to 2.4.1)

Timeline and source

Published on 5 December 2025 and last revised on 17 June 2026. No public exploit is currently recorded for this entry. A vendor advisory or fix has been published. Record sourced from NVD.

References

github.com
github.com
github.com
hackerone.com

Details

Severity LOW
CVSS Score 3.1
CVSS Vector CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:N
CWE CWE-639
Public Exploit ✅ No
Source NVD
Published 2025-12-05
Updated 2026-08-11
Modified 2026-06-17

Affected Packages

Software From version Fixed in
two-factor-webauthn 2.0.0 2.4.1

Free Vulnerability Check

Is your site affected by CVE-2025-66558?

BotEraser helps you identify potentially vulnerable plugins and themes by checking your installation against CVE-2025-66558 and other known CVE records.

Scan My Site Free →

No credit card required  ·  Results in minutes

ⓘ Data Notice: The information presented above has been compiled from publicly available internet sources. Boteraser aggregates this data solely for informational purposes and does not independently classify, evaluate, or endorse any findings about the vulnerabilities listed. The accuracy and completeness of this information is the sole responsibility of the original publishers. Boteraser and its operators accept no liability for any decisions made based on this data.