CVE-2026-86417 MISP CVE debrief

Who should care

MISP administrators and users who require email address visibility control. Defenders should verify MISP versions and configurations, implement centralized authorization for email disclosure, and monitor for unauthorized access. MISP users who have access to the REST/JSON representation of the dashboard templates.

Why it matters

CVE-2026-86417 affects MISP versions ≤2.5.45, allowing potential unauthorized access to email addresses through REST/JSON representation. Defenders should verify MISP versions and configurations, implement centralized authorization for email disclosure, and monitor for unauthorized access.

• Potential unauthorized access to email addresses
• Inconsistent email disclosure policy across MISP interfaces
• Need for verification of MISP version and configuration
• Potential for exploitation through REST/JSON representation

Technical summary

MISP versions ≤2.5.45 have an inconsistent enforcement of email-address visibility in DashboardsController::listTemplates(). The query always fetched User.email, while redaction happened only inside the non-REST rendering branch. As a result, the same authenticated user who saw redacted data in the normal HTML interface could request the REST/JSON representation and receive template owners’ email addresses without the intended privilege check. The fix moves the decision to a centralized User::canSeeEmails() authorization helper.

Defensive priority

Defenders should prioritize verifying MISP versions and configurations.

Recommended defensive actions

• Verify MISP version and configuration for vulnerable instances
• Implement centralized authorization for email disclosure
• Monitor for unauthorized access to email addresses
• 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 inconsistent enforcement of email-address visibility in MISP DashboardsController::listTemplates(). The CVE record was published on 2026-09-07T13:20:40.393Z and has not been modified since then. The NVD entry provides additional information on the vulnerability. The fix moves the decision to a centralized User::canSeeEmails() authorization helper.

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.