CVE-2026-69257 FlowiseAI CVE debrief

Who should care

Flowise users and administrators should assess their exposure and verify their version of Flowise. This vulnerability may impact organizations using Flowise for building customized large language model flows, especially those with exposed Flowise instances or integrations with internal services.

Why it matters

CVE-2026-69257 is a high-severity vulnerability in Flowise that could allow attackers to bypass IP deny lists by manipulating DNS resolution. Flowise users and administrators should verify their version and configurations to prevent potential exploitation.

• Potential bypass of IP deny lists for Flowise instances
• Possible unauthorized access to internal services or localhost
• Potential exposure of cloud metadata endpoints
• Verification priority for Flowise version and IP deny list configurations

Technical summary

The Flowise application, prior to version 3.1.3, contains a vulnerability in its httpSecurity.ts module. This module fails to properly normalize IPv4-mapped IPv6 addresses before checking them against a deny list. Specifically, addresses like ::ffff:127.0.0.1 and ::ffff:169.254.169.254 are reported as IPv6 by the ipaddr.js library, while the deny list entries are in IPv4 CIDR format. This discrepancy allows an attacker who controls DNS resolution for certain hostnames used by Flowise components (such as the HTTP Node, API Chain, Document Loader, or MCP tool) to return an AAAA record for an IPv4-mapped target. This could potentially cause requests to bypass the IP deny list and reach localhost, internal services, or cloud metadata endpoints.

Defensive priority

High priority for Flowise users to verify and update

Recommended defensive actions

• Verify Flowise version and update to 3.1.3 or later if necessary
• Review and update IP deny lists to ensure proper handling of IPv4-mapped IPv6 addresses
• Monitor Flowise instances for potential exploitation attempts
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record and NVD entry provide details on the vulnerability in Flowise versions prior to 3.1.3. The issue involves improper handling of IPv4-mapped IPv6 addresses in the httpSecurity.ts module, which could allow attackers to bypass IP deny lists.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.