CVE-2026-116469 MISP CVE debrief

Who should care

Defenders responsible for MISP instances and threat-intelligence data distribution should assess exposure and prioritize remediation. This includes verifying MISP Guard configurations and updating to a fixed version to prevent potential unauthorized disclosure of threat-intelligence data.

Why it matters

The case-sensitivity flaw in MISP Guard allows attackers to bypass security policies, potentially leading to unauthorized disclosure of threat-intelligence data. Defenders should prioritize verifying configurations and updating to a fixed version.

• Potential unauthorized disclosure of threat-intelligence data.
• Bypass of configured security policies due to case-sensitivity flaw.
• Forwarding of events carrying non-allowed TLP markings or blocked attribute categories.

Technical summary

MISP Guard, a proxy-based security filter for MISP feed distribution, contains a case-sensitivity flaw in multiple policy enforcement checks. The functions check_required_taxonomy_exists, check_required_taxonomy_tags_allowed, check_blocked_attribute_categories, and check_blocked_analyst_data_sharing_groups_uuids performed case-sensitive string comparisons when matching event tags, attribute categories, and sharing-group UUIDs against configured allow/block lists. This flaw allows attackers to bypass security policies, potentially leading to unauthorized disclosure of threat-intelligence data.

Defensive priority

Defenders should prioritize verifying MISP Guard configurations and updating to a fixed version.

Recommended defensive actions

• Verify MISP Guard configurations to ensure correct policy enforcement.
• Update MISP Guard to a version that fixes the case-sensitivity flaw.
• Monitor MISP instance event creations and modifications 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 case-sensitivity flaw in MISP Guard. The flaw exists in multiple policy enforcement checks, including check_required_taxonomy_exists, check_required_taxonomy_tags_allowed, check_blocked_attribute_categories, and check_blocked_analyst_data_sharing_groups_uuids. These functions performed case-sensitive string comparisons when matching event tags, attribute categories, and sharing-group UUIDs against configured allow/block 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.