Skip to main content
No exploitation reportedFix available

CVE-2026-18916

No exploitation reported by the sources we read.

  • Published2026-08-26
  • Fixed in4.15.1
  • WeaknessCWE-191

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

Any remote client can crash a NSD serve child, by throttling the TCP receive window after a TCP query. By continuously crashing the serve childs, the remote client can denial all TCP service to this NSD instance.

Timeline

dates in UTC
  1. 2026-08-2609:16CVE publishedNVD

Versions per branch

NVD
Nlnetlabs nsd
BranchAffectedFixed in
4.15≥ 3.2.11, < 4.15.14.15.1

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Products declared by the CNA1 product

As NLnet Labs, the CNA that assigned this CVE, declared them in the CVE record; versions as written.

  • NLnet Labs NSDother versions: not affected
    Affected
    • ≥ 3.2.11, < 4.15.1fixed in 4.15.1semver

Source: the CNA record (CVE Program), © The MITRE Corporation,CVE Terms of UseCVE recordupdated 2026-08-26

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

  • nsdUbuntu:Pro:26.04:LTSall versions · no fixed version listed
  • nsdUbuntu:Pro:24.04:LTSall versions · no fixed version listed
  • nsdUbuntu:Pro:22.04:LTSall versions · no fixed version listed
  • nsdUbuntu:Pro:20.04:LTSall versions · no fixed version listed
  • nsdUbuntu:Pro:18.04:LTSall versions · no fixed version listed
  • nsdUbuntu:Pro:16.04:LTSall versions · no fixed version listed
  • nsdUbuntu:26.10all versions · no fixed version listed
  • nsdDebian:14all versions · fixed in 4.15.1-1

2 more package ranges on OSV.dev

Vendor advisories

  • CVE-2026-18916 Red Hat Product Security

    nsd: NSD: Denial of Service due to TCP receive window throttling

Full record on NVD

Fix

  1. Update Nlnetlabs nsd to 4.15.1

Advisories and patches

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof of concept
Metasploit modules
none listed
Metasploit Framework

Sources

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS 4.0 vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Published
2026-08-26
Last Modified
2026-09-08
NVD status
Analyzed
GitHub Advisory
GHSA-m6mr-q7j3-3rc6

Frequently asked questions

What is CVE-2026-18916?

Any remote client can crash a NSD serve child, by throttling the TCP receive window after a TCP query. By continuously crashing the serve childs, the remote client can denial all TCP service to this NSD instance.

Is CVE-2026-18916 actively exploited?

Active exploitation of CVE-2026-18916 has not been confirmed. Its EPSS score was 0.5% on 2026-11-09, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2026-18916?

CVE-2026-18916 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Running nsd? Hear about its next vulnerability

Surveillance reads the versions in your stack — a domain, a lockfile or a list — checks each CVE against the ranges its sources publish, and alerts you when one you run is exploited or enters CISA KEV. A version it cannot read stays « version not verified ».

Get alerts for this productCISA KEV additions, November 2026Search CVEs

No credit card required · No monthly cap on website lookups · 250 API requests/month

Go further

Related vulnerabilities

Same product first, then the same vendor advisory and the same publication week.

Back to CVE Database

Sources for this record