CVE-2026-43914

Description

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.

Weakness classification

• security-advisories@github.com: CWE-307

Primary references

• security-advisories@github.com — Issue Tracking, Patch
• security-advisories@github.com — Product, Release Notes
• security-advisories@github.com — Exploit, Patch, Vendor Advisory
• 134c704f-9b21-4f2e-91b3-4a467353bcc0 — Exploit, Patch, Vendor Advisory