Denial of Service Vulnerability in NSD Server by NLnet Labs
CVE-2026-18916

6.9MEDIUM

Key Information:

Vendor

Nlnet Labs

Status
Nsd
Vendor
CVE Published:
26 August 2026

What is CVE-2026-18916?

A vulnerability in NSD Server allows remote clients to exploit a weakness by throttling the TCP receive window following a TCP query. This action can lead to repeated crashes of the server's child processes, resulting in a denial of service. Continuous exploitation can effectively disrupt all TCP services of the affected NSD instance, presenting significant challenges for system availability and reliability.

Affected Version(s)

NSD 3.2.11 < 4.15.1

References

https://www.nlnetlabs.nl/downloads/nsd/CVE-2026-18916.txt
vendor-advisory

CVSS V4

Score:
6.9
Severity:
MEDIUM
Confidentiality:
None
Integrity:
None
Availability:
Low
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Akhil Koul (https://github.com/akoul)
.