CVE-2026-42004 Affecting dnsdist package, versions <1.9.15-0+deb13u1


Severity

Recommended
low

Based on default assessment until relevant scores are available.

Threat Intelligence

EPSS
0.16% (6th percentile)

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  • Snyk IDSNYK-ECHOLATEST-DNSDIST-18578979
  • published7 Aug 2026
  • disclosed25 Jun 2026

Introduced: 25 Jun 2026

CVE-2026-42004  (opens in a new tab)

How to fix?

Upgrade Echo:latest dnsdist to version 1.9.15-0+deb13u1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream dnsdist package and not the dnsdist package as distributed by Echo. See How to fix? for Echo:latest relevant fixed versions and status.

An attacker can send a crafted EDNS OPT record that will be ignored by DNSdist’s filtering rules, but will be rewritten as a valid OPT record when EDNS Client Subnet is inserted, causing the backend to see the EDNS option(s) that DNSdist did not filter.