Skip to main content

Over 150 LLM Providers · Over 5,300 Models The most extensible AI-powered pentesting platform. Open source. Star on GitHub

CVE-2026-42960

10.0 · CRITICAL
Published May 20, 2026 nlnetlabs CWE-349

Overview

CVE-2026-42960 is a critical-severity vulnerability affecting nlnetlabs unbound. It was published on May 20, 2026 and has a CVSS 3.1 base score of 10.0 (CRITICAL).

This vulnerability has a CVSS 3.1 base score of 10.0, rated CRITICAL. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.

Technical Description

NLnet Labs Unbound up to and including version 1.25.0 is vulnerable to poisoning via promiscuous records for the authority section. Promiscuous RRSets that complement DNS replies in the authority section can be used to trick Unbound to cache such records. If an adversary is able to attach such records in a reply (i.e., spoofed packet, fragmentation attack) he would be able to poison Unbound's cache. A malicious actor can exploit the possible poisonous effect by injecting RRSets other than NS that are also accompanied by address records in a reply, for example MX. This could be achieved by trying to spoof a reply packet or fragmentation attacks. Unbound would then accept the relative address records in the additional section and cache them if the authority RRSet has enough trust at this point, i.e., in-zone data for the delegation point. Unbound 1.25.1 contains a patch with a fix that disregards address records from the additional section if they are not explicitly relevant only to auth

Remediation

Check the references section for vendor advisories and patches from nlnetlabs. Update unbound to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

Affected Products

Vendor Product Versions Status
nlnetlabs unbound >= 0, < 1.25.1 Affected

Frequently Asked Questions

What is CVE-2026-42960?

CVE-2026-42960 is a critical-severity vulnerability affecting nlnetlabs unbound. It was published on May 20, 2026 and has a CVSS 3.1 base score of 10.0 (CRITICAL).

How severe is CVE-2026-42960?

This vulnerability has a CVSS 3.1 base score of 10.0, rated CRITICAL. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.

How do I fix or remediate CVE-2026-42960?

Check the references section for vendor advisories and patches from nlnetlabs. Update unbound to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

How can CyberStrike help with CVE-2026-42960?

CyberStrike's AI-powered security agents can automatically detect CVE-2026-42960 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.