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PatchSiren cyber security CVE debrief

CVE-2026-42390 PowerDNS CVE debrief

A vulnerability in the ZONEMD validation process allows an invalid zone to pass validation. This issue is relevant only if ZoneToCache is configured with ZONEMD validation. The vulnerability could potentially lead to security risks if not properly addressed. Defenders responsible for configuring and maintaining ZoneToCache with ZONEMD validation should assess their exposure and verify their configurations to ensure the security of their systems. This involves reviewing the current configurations, understanding the potential impact of the vulnerability, and taking necessary steps to mitigate any risks. It is essential to prioritize verifying ZoneToCache configurations and ensuring

Vendor
PowerDNS
Product
Recursor
CVSS
MEDIUM 5.3
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-25
Original CVE updated
2026-10-25
Advisory published
2026-06-25
Advisory updated
2026-10-25

Who should care

Defenders responsible for configuring and maintaining ZoneToCache with ZONEMD validation should assess their exposure and verify their configurations.

Why it matters

Defenders should care about CVE-2026-42390 because it allows invalid zones to pass ZONEMD validation, potentially leading to security risks. Those responsible for configuring and maintaining ZoneToCache with ZONEMD validation should assess their exposure and verify their configurations.

  • Potential security risks due to invalid zones passing validation
  • Need for verification of ZoneToCache configurations and ZONEMD validation settings
  • Possible impact on DNS resolution and security

Technical summary

The vulnerability allows an invalid zone to pass ZONEMD validation if ZoneToCache is configured with ZONEMD validation. The CVSS score is 5.3, and the severity is MEDIUM. This issue could have significant implications for the security of systems using ZoneToCache with ZONEMD validation. Affected systems may be vulnerable to security risks if not properly configured or updated. It is crucial to review and update configurations to prevent potential issues and monitor for potential security advisories from the vendor. The vulnerability highlights the importance of

Defensive priority

Defenders should prioritize verifying ZoneToCache configurations and ensuring proper ZONEMD validation.

Recommended defensive actions

  • Verify ZoneToCache configurations and ZONEMD validation settings
  • Review and update configurations to prevent potential issues
  • Monitor for potential security advisories from the vendor

Evidence notes

The CVE record and NVD entry provide limited information about the vulnerability. Further investigation is required to determine the affected versions and potential impact.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-42390 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-42390

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-42390 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-42390

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental 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.