CVE-2026-43914: Dani-Garcia Vaultwarden

Critical severity, CVSS 9.8. EPSS: 0.5% chance of exploitation in the next 30 days.

Vaultwarden is a Bitwarden-compatible server written in Rust. Prior to 1.35.4, there is a security vulnerability in Vaultwarden that allows bypassing the login brute-force protection if email 2fa is enabled. If email 2fa is enabled, the unprotected 2fa-function send_email_login (email.rs, api endpoint /api/two-factor/send-email-login) also acts as an oracle determining whether a username-password combination is correct. An attacker can abuse that endpoint to brute-force passwords without rate-limiting. This works even for users who don't have email 2fa configured. This vulnerability is fixed in 1.35.4.

Affected products

• Dani-Garcia Vaultwarden: before 1.35.4 (fixed in 1.35.4)

Published 2026-05-11. Last modified 2026-06-17.