CVE-2026-116678
Description
A flaw was found in Vaultwarden. When internal icon downloading is enabled, the server fails to properly validate secondary favicon web addresses extracted from untrusted pages against network access restrictions. A remote, unauthenticated attacker can exploit this vulnerability to cause information disclosure by providing a webpage containing direct IP literal addresses that point to loopback or private networks. This induces the server to issue unauthorized internal HTTP requests (Server-Side Request Forgery, or SSRF), enabling the attacker to probe restricted internal services or access sensitive data.
Statement
A Server-Side Request Forgery (SSRF) flaw was found in Vaultwarden's icon downloading functionality. When internal icon downloading is enabled, secondary favicon web addresses parsed from attacker-controlled HTML pages are not validated against network access restrictions. A remote, unauthenticated attacker can provide a webpage whose favicon uses an IP-literal URL pointing to loopback or private networks, inducing the Vaultwarden server to issue unauthorized internal HTTP requests and potentially probe restricted internal services or access sensitive data. This issue is fixed in version 1.37.0. No Red Hat product ships vaultwarden; affected Fedora/EPEL community packages are handled through the community tracker workflow.
Mitigation
Upgrade to Vaultwarden 1.37.0 or later. Alternatively, disable internal icon downloading by setting DISABLE_ICON_DOWNLOAD=true, or configure ICON_SERVICE to use an external icon service provider, which avoids the vulnerable internal icon fetching code path.
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Application Data
Integrity
Technical Impact: Execute Unauthorized Code or Commands
Access Control
Technical Impact: Bypass Protection Mechanism
By providing URLs to unexpected hosts or ports, attackers can make it appear that the server is sending the request, possibly bypassing access controls such as firewalls that prevent the attackers from accessing the URLs directly. The server can be used as a proxy to conduct port scanning of hosts in internal networks, use other URLs such as that can access documents on the system (using file://), or use other protocols such as gopher:// or tftp://, which may provide greater control over the contents of requests.
Frequently Asked Questions
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