CVE-2026-43914 Vaultwarden: Brute-force protection bypass vulnerability

What is CVE-2026-43914?

CVE-2026-43914 is a high-severity vulnerability in dani-garcia vaultwarden, published on 11 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official 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: CWE-307

Which versions are affected by CVE-2026-43914?

It affects 1 product.

Products include Dani-Garcia Vaultwarden.

How do I fix CVE-2026-43914?

No fix has been published for CVE-2026-43914 yet. Limit exposure of the affected software until one is available.

Is CVE-2026-43914 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-43914 exists.

Public exploit code: 1 proofs of concept on GitHub.

Other vulnerabilities in dani-garcia vaultwarden

• CVE-2024-55225 Vaultwarden vulnerable to user impersonation Critical 9.8
• CVE-2024-55224 Vaultwarden HTML injection vulnerability Critical 9.6
• CVE-2024-39924 Privilege escalation in n/a High 8.8
• CVE-2026-43912 Vaultwarden: Cross-Org Group Binding Enables Unauthorized Read And Write Access Into Another Organization High 8.7
• CVE-2026-27802 Vaultwarden: Privilege Escalation via Bulk Permission Update to Unauthorized Collections by Manager High 8.3

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-c5rv-q295-7w4g.