CVE-2026-19401

Summary

Any remote client can crash a (debugging/non-release build type) NSD serve child by sending it a special crafted message with a specially tuned number of DNS Cookie options (17 when UDP payload size is 512). By continuously crashing the serve childs, the remote client can severely hamper or, when positioned sufficiently close, deny all DNS service.

Affected Software

VendorProductVersion RangeStatus
NLnet LabsNSD4.3.7 < 4.15.1affected

Weaknesses

  • CWE-617: CWE-617 Reachable Assertion
  • CWE-400: CWE-400 Uncontrolled Resource Consumption

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

References