Vulnerability in dani-garcia vaultwarden

[ Why it matters ]Priority signals

• Public proof-of-concept exploit exists (CISA SSVC)

[ Description ]Official description

Vaultwarden is a Bitwarden-compatible server written in Rust. Prior to version 1.37.0, the Vaultwarden icon downloader validates the initial icon host and DNS results but passes favicon URLs parsed from attacker-controlled HTML to get_page_with_referer() without applying should_block_host() to the second-stage host. This flaw bypasses the remediation for CVE-2026-47160, which covered decimal, hexadecimal, octal, and IPv4-mapped IPv6 host normalization, because the second-stage IP-literal favicon fetch does not invoke the custom DNS resolver. A remote unauthenticated attacker can provide a public page whose favicon uses an IP-literal URL, allowing the Vaultwarden server to reach loopback or private and internal addresses. The issue affects instances with internal icon downloading enabled and can expose internal responses that resemble supported images or reveal reachability through timing, status, and cache behavior. This issue is fixed in version 1.37.0.

[ Fixes ]Fixes and patches

No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.

[ Advisories ]Government CERT advisories

• BSI CERT-Bund27 Oct 2026WID-SEC-2026-4219

  Vaultwarden: Vulnerability allows bypassing security measures Translated from German

  CVE-2026-116678

[ References ]References

• github.com/dani-garcia/vaultwarden/commit/46ae59eaf444f0ae0a799070cf2bd6c415284a51
• github.com/dani-garcia/vaultwarden/pull/7472
• github.com/dani-garcia/vaultwarden/releases/tag/1.37.0
• github.com/dani-garcia/vaultwarden/security/advisories/GHSA-hw4g-2v3f-74x5