CVE-2026-42004 — LOW (3.7) — White Hats Nepal

Vulnerability 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.

CVSS Score

3.7

LOW

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

Attack Vector

NETWORK

Attack Complexity

HIGH

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality

NONE

Integrity

LOW

Availability

NONE

Related Weaknesses (CWE)

CWE-115

References

https://www.dnsdist.org/security-advisories/powerdns-advisory-for-dnsdist-2026-0

FAQ

What is CVE-2026-42004?

CVE-2026-42004 is a vulnerability with a CVSS score of 3.7 (LOW). 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 t...

How severe is CVE-2026-42004?

CVE-2026-42004 has been rated LOW with a CVSS base score of 3.7/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-42004?

Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.