CVE-2026-40011 PowerDNS CVE debrief

Who should care

Defenders responsible for DNS infrastructure and prometheus monitoring should assess exposure and verify DNS query patterns. This includes operators managing DNS infrastructure, security teams monitoring prometheus endpoints, and vulnerability management teams reviewing and updating DNSdist configurations. These teams should review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance. They should also plan

Why it matters

CVE-2026-40011 is a low-severity vulnerability in DNSdist that allows an attacker to trigger a dynamic block with invalid output in the prometheus endpoint by sending a large number of crafted DNS queries. Defenders responsible for DNS infrastructure and prometheus monitoring should assess exposure and verify DNS query patterns.

• Verify DNS query patterns to detect potential attacks
• Monitor prometheus endpoint for unusual output
• Review and update DNSdist configurations

Technical summary

CVE-2026-40011 is a vulnerability in DNSdist that allows an attacker to trigger a dynamic block with invalid output in the prometheus endpoint by sending a large number of crafted DNS queries. This vulnerability impacts DNS infrastructure and prometheus monitoring. The vulnerability can be triggered by sending a large number of crafted DNS queries, which could lead to invalid output in the prometheus endpoint. Defenders should assess exposure and verify DNS query patterns to mitigate potential attacks. The CVE record and NVD entry provide limited information about the vulnerability.

Defensive priority

Verify and monitor DNS query patterns

Recommended defensive actions

• Verify DNS query patterns to detect potential attacks
• Monitor prometheus endpoint for unusual output
• Review and update DNSdist configurations
• 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 entry provide limited information about the vulnerability. The DNSdist advisory is referenced but not detailed. Evidence is limited to public CVE and NVD records. Defenders should verify DNS query patterns and monitor prometheus endpoint output for unusual activity. The vulnerability allows an attacker to trigger a dynamic block with invalid output in the prometheus endpoint by sending a large number of crafted DNS queries.

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.