CVE-2026-42004 Details
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.
A vulnerability exists in PowerDNS DNSdist versions through 2.0.6 and 1.9.14, allowing an attacker to send a crafted EDNS OPT record that bypasses DNSdist's filtering rules. When EDNS Client Subnet is added, the ignored OPT record is rewritten and sent to the backend, exposing EDNS options that should have been filtered out.
Users are advised to upgrade to PowerDNS DNSdist versions 1.9.15 or 2.0.7. Alternatively, do not rely on EDNS option filtering or disable EDNS Client Subnet insertion.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Jun 25, 2026CISA-ADP
Assessed Jun 25, 2026References to Advisories, Solutions, and Tools
By selecting these links, you will be leaving this site. These are references gathered from the official CVE record and are not endorsed by Volerion.
| URL | Source(s) | Tag(s) |
|---|---|---|
| https://www.dnsdist.org/security-advisories/powerdns-advisory-for-dnsdist-2026-09.html | [email protected] | AdvisoryBundleRemedyVendor |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-115 | Misinterpretation of Input | CISA-ADP |
Affected Products
| Product | Versions |
|---|---|
| PowerDNS DNSdist | <= 2.0.6 (semver) <= 1.9.14 (semver) |
CPE
Remediation
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Change History
2 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jun 25, 2026 | CVE Modified | CISA-ADP |
| Jun 25, 2026 | New CVE Received | [email protected] |