CVE-2026-86419 MISP CVE debrief

Who should care

MISP administrators and users, security teams, and IT personnel responsible for MISP deployment and maintenance. These stakeholders should be aware of the potential security risks associated with CVE-2026-86419 and take necessary actions to prevent credential exposure, internal network resource access, and other security risks. They should review and update MISP to version 2.5.46 or later, restrict access to MISP feed retrieval and TAXII discovery, and to

Why it matters

CVE-2026-86419 is a high-severity vulnerability in MISP that requires attention from administrators and security teams to prevent potential credential exposure, internal network resource access, and other security risks.

• Potential credential exposure or forwarding to unintended hosts
• Possible internal network resource access via SSRF
• Required verification of MISP version and configuration
• Potential impact on MISP feed retrieval and TAXII discovery functionality

Technical summary

MISP contains insufficient validation of server-side outbound HTTP destinations in feed retrieval and TAXII discovery functionality. The fix adds redirect validation, blocks internal destinations for cross-host redirects, strips configured feed credentials before following redirects to another host, and pins validated DNS results. This hardening effort addresses alternate-address representations, DNS-related bypasses, unsafe redirects, internal-host access, and cross-host credential forwarding in MISP's outbound URL handling.

Defensive priority

High

Recommended defensive actions

• Review and update MISP to version 2.5.46 or later
• Restrict access to MISP feed retrieval and TAXII discovery functionality
• Monitor MISP logs for suspicious activity
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
• Review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance
• Plan vendor-supported updates or mitigations through normal change control where exposure is confirmed
• Check relevant monitoring, detection, and logs for exposed assets that need extra review

Evidence notes

The CVE record and NVD detail page provide information on the vulnerability in MISP. The fix adds redirect validation, blocks internal destinations for cross-host redirects, strips configured feed credentials before following redirects to another host, and pins validated DNS results.

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.