CVE-2026-43914
Vaultwarden: Brute-force protection bypass vulnerability
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.
INFO
Published Date :
May 11, 2026, 11:20 p.m.
Last Modified :
May 13, 2026, 7:35 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | [email protected] | ||||
| CVSS 3.1 | CRITICAL | [email protected] |
Solution
- Update Vaultwarden to version 1.35.4.
- Verify brute-force protection is enforced.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-43914.
| URL | Resource |
|---|---|
| https://github.com/dani-garcia/vaultwarden/pull/6867 | Issue Tracking Patch |
| https://github.com/dani-garcia/vaultwarden/releases/tag/1.35.4 | Product Release Notes |
| https://github.com/dani-garcia/vaultwarden/security/advisories/GHSA-c5rv-q295-7w4g | Exploit Patch Vendor Advisory |
| https://github.com/dani-garcia/vaultwarden/security/advisories/GHSA-c5rv-q295-7w4g | Exploit Patch Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-43914 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-43914
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-43914 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-43914 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
May. 13, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Added CPE Configuration OR *cpe:2.3:a:dani-garcia:vaultwarden:*:*:*:*:*:*:*:* versions up to (excluding) 1.35.4 Added Reference Type GitHub, Inc.: https://github.com/dani-garcia/vaultwarden/pull/6867 Types: Issue Tracking, Patch Added Reference Type GitHub, Inc.: https://github.com/dani-garcia/vaultwarden/releases/tag/1.35.4 Types: Product, Release Notes Added Reference Type CISA-ADP: https://github.com/dani-garcia/vaultwarden/security/advisories/GHSA-c5rv-q295-7w4g Types: Exploit, Patch, Vendor Advisory Added Reference Type GitHub, Inc.: https://github.com/dani-garcia/vaultwarden/security/advisories/GHSA-c5rv-q295-7w4g Types: Exploit, Patch, Vendor Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
May. 12, 2026
Action Type Old Value New Value Added Reference https://github.com/dani-garcia/vaultwarden/security/advisories/GHSA-c5rv-q295-7w4g -
New CVE Received by [email protected]
May. 11, 2026
Action Type Old Value New Value Added 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. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L Added CWE CWE-307 Added Reference https://github.com/dani-garcia/vaultwarden/pull/6867 Added Reference https://github.com/dani-garcia/vaultwarden/releases/tag/1.35.4 Added Reference https://github.com/dani-garcia/vaultwarden/security/advisories/GHSA-c5rv-q295-7w4g