CVE-2026-31835

Vaultwarden is a Bitwarden-compatible server written in Rust. In versions 1.35.4 and earlier, the WebAuthn authentication flow in `validate_webauthn_login()` updates persistent credential metadata (1backup_eligible1 and 1backup_state flags1) based on unverified `authenticatorData` before signature validation is performed. An attacker who knows a user's password but cannot produce a valid WebAuthn signature can permanently modify the stored backup flags for that user's credential. If signature verification fails, the database update is not rolled back. This can result in a persistent denial of service of WebAuthn two-factor authentication for affected credentials. This issue has been fixed in version 1.35.5.

The following products are affected by CVE-2026-31835 vulnerability.

Here, you will find a curated list of external links that provide in-depth information to CVE-2026-31835.

URL	Resource
https://github.com/dani-garcia/vaultwarden/releases/tag/1.35.5
https://github.com/dani-garcia/vaultwarden/security/advisories/GHSA-x7g7-cgx5-jhx2