CVE-2026-116678

Name of the Vulnerable Software and Affected Versions Vaultwarden versions prior to 1.37.0

Description The icon downloader fails to apply the should block host() check to the second-stage host when processing favicon URLs parsed from attacker-controlled HTML passed to get page with referer(). This allows a remote unauthenticated attacker to use an IP-literal URL in a favicon to bypass host normalization and force the server to reach loopback, private, or internal addresses. This issue occurs on instances where internal icon downloading is enabled and can lead to the exposure of internal responses or reveal internal network reachability through timing, status, and cache behavior.

Recommendations Update to version 1.37.0. Disable internal icon downloading as a temporary mitigation measure.