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High · 7.3 Public exploit CVE-2026-43914 EUVD-2026-29342

Vaultwarden: Brute-force protection bypass vulnerability

Published May 11, 2026 · Updated May 12, 2026 · Assigned by GitHub_M

Vendor: dani-garcia Product: vaultwarden

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.

Affected products

VendorProductAffectedFixed
dani-garcia vaultwarden < 1.35.4 —

Public exploits

Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.

Third-party code, not reviewed by us. Public PoCs are sometimes fake or contain malware. Read the code first and run it only in an isolated lab, against systems you are authorised to test.

GitHub 1 repository

  • Boreas37/CVE-2026-43914-PoC ★ 1 · Aug 24, 2026

    PoC for CVE-2026-43914: Vaultwarden <1.35.4 email-2FA brute-force bypass password oracle. Stdlib-only Python.

Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.

Advisories 1

References