CVE-2026-42389
Reject more queries with invalid header values
MEDIUM
5.3
CVSS Score
Published: June 25, 2026 at 01:16 PM UTC
Updated: October 25, 2026 at 11:10 PM UTC
2 products affected across 1 vendorRecursorAuthoritative
Using Recursor by PowerDNS?
Get instant alerts when new vulnerabilities affect Recursor - before attackers find them.
Real-time alertsTrack your software stackFree plan available
Severity
MEDIUM5.3
Exploit prediction
EPSS 0.3%
SSVC
No known exploit
Description
This fix provides extra hardening for the 5.4.x branch by doing extra validation of incoming answers from authoritative servers.
Affected
Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.
5.4.0 ≤ v < 5.4.35.4.0
Affected range stops below 5.4.3, so it looks safe — our inference, not a vendor statement
All versions
Remediation
No guide yetNo remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.
References (1)
SSVC — Action Prioritization
SSVCNo known exploitAutomatablePartial impact
SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.
CVSS
5.3MEDIUMOX
- Attack Vector
- NETWORK
- Complexity
- LOW
- Privileges
- NONE
- User Interaction
- NONE
- Scope
- UNCHANGED
- Confidentiality
- NONE
- Integrity
- LOW
- Availability
- NONE
Vector?
Quick Info
StatusDEFERRED
CWE
CWE-20
Get alerted
Stop reading CVE feeds looking for your own stack
Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.
Free plan, no card