Bug 2562195 (CVE-2026-116678)

Summary:	CVE-2026-116678 vaultwarden: vaultwarden: Server-Side Request Forgery via favicon IP literal URLs
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security <prodsec-ir-bot>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	Keywords:	Security
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Hardware:	All
OS:	Linux
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Doc Text:	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.	Story Points:	---
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
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Bug Depends On:	2562423, 2562424, 2562425, 2562426, 2562427
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Description OSIDB Bzimport 2026-10-27 18:16:01 UTC

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.