CVE-2026-69257

Flowise, an open-source drag-and-drop UI for building LLM workflows, failed to normalize IPv4-mapped IPv6 addresses (e.g., ::ffff:169.254.169.254) in its HTTP security module (httpSecurity.ts) before applying IP deny-list checks, causing IPv4 CIDR rules to be skipped for these addresses. An attacker who controls DNS resolution for a hostname used in components such as the HTTP Node, API Chain, Document Loader, or MCP tools could return a AAAA record resolving to an IPv4-mapped address and bypass SSRF protections, redirecting requests to localhost, internal services, or cloud metadata endpoints. Successful exploitation can expose sensitive internal data or cloud credentials (high confidentiality and integrity impact), though it requires the attacker to influence DNS for a hostname used by the application (AT:P) and some level of privileges (PR:L). All self-hosted Flowise deployments prior to version 3.1.3 are affected; the flaw is fixed in version 3.1.3. Technical details are public via a GitHub security advisory, but EPSS is low (0.3%) and there is no evidence of exploitation in the wild.

What to do: Upgrade Flowise to version 3.1.3 or later, which normalizes IPv4-mapped IPv6 addresses before deny-list checks. Until patched, restrict Flowise's outbound network access at the network layer (deny egress to link-local 169.254.169.254, loopback, and internal RFC1918 ranges regardless of protocol family) and validate or pin DNS for hostnames used in HTTP Nodes, API Chains, Document Loaders, and MCP tools. Review logs for flows that resolved attacker-controllable hostnames or fetched metadata/internal endpoints.