Input Validation Flaw in PowerDNS Recursor Affects Server Stability
CVE-2026-42387

5.9MEDIUM

Key Information:

Vendor

Powerdns

Status
Recursor
Vendor
CVE Published:
25 June 2026

What is CVE-2026-42387?

A vulnerability exists in PowerDNS Recursor where a malicious authoritative server can send a specially crafted zone through the ZoneToCache function. This flaw is a result of insufficient input validation that can lead to a crash of the Recursor, potentially disrupting DNS resolution services. Implementing proper input validation checks is crucial to mitigate this risk and ensure stable server performance.

Affected Version(s)

Recursor 5.2.0 < 5.2.11

Recursor 5.3.0 < 5.3.8

Recursor 5.4.0 < 5.4.3

References

https://docs.powerdns.com/recursor/security-advisories/po...

CVSS V3.1

Score:
5.9
Severity:
MEDIUM
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
High
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

nurmukhammyed
.