Vulnerability in Vaultwarden (CVE-2026-43914)
Summary
Vulnerability in Vaultwarden (CVE-2026-43914). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 1.35.4 or later.
Original description
The description as published by the source.
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.
Source: NIST National Vulnerability Database NVD
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-43914 has been found in Vaultwarden.
Risk of unauthorized operations or information disclosure. CVSS score: 7.3/10.
What to do: upgrade Vaultwarden to 1.35.4 or later.
If unsure, ask your IT team or search "Vaultwarden CVE-2026-43914" on the vendor's site.
CVE-2026-43914 (Vaultwarden) — CWE-307 / CVSS v3 7.3
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Patched: 1.35.4 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-307) exists in Vaultwarden.
Check the vendor advisory for the affected versions of Vaultwarden.
Severity: High (CVSS 7.3/10). Risk of unauthorized operations or information disclosure.
Update to 1.35.4.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'Vaultwarden' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'Vaultwarden' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
Vaultwardenを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade Vaultwarden to 1.35.4ステージング環境で 1.35.4 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
References
- exploit github.com
- patch security-advisories@github.com
- web security-advisories@github.com