Is CVE-2026-42004 in the CISA KEV catalog?

No. CVE-2026-42004 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2026-42004?

CVE-2026-42004 has a CVSS v3 base score of 3.7 (LOW).

What is the EPSS score for CVE-2026-42004?

CVE-2026-42004 has an EPSS score of 0.16% (6th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2026-42004?

Upgrade dnsdist on debian 13 to 1.9.15-0+deb13u1 or later.

CVE & CISA-KEV Catalog

CVE-2026-42004

LOW

3.7

CVSS v3

NVD

Description

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.

CWE-115

How to fix

Remediation Available

dnsdistDebian

Fixed in:1.9.15-0+deb13u1CVE-2026-42004

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityHigh

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityNone

IntegrityLow

AvailabilityNone

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N

Exploit Intelligence

0.16%probability of exploitation in 30 days

6thpercentile

Low risk: more likely to be exploited than 6% of all known CVEs.

References

Other references1

dnsdist.org

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-06-25.