CVE-2026-55708: nlnet labs unbound

Vulnerability summary

CVE-2026-55708 is a low (CVSS 3.1) vulnerability in nlnet labs unbound. EPSS estimates a 0.15% chance of exploitation in the next 30 days, higher than 3.7% of scored vulnerabilities.

Timeline

1. 22-07-2026
   PublishedVulnerability first disclosed.
2. 22-07-2026
   Last modifiedVulnerability information updated.

Description

In NLnet Labs Unbound 1.6.0 up to and including 1.25.1, the 'view_local_data' and 'view_local_datas' commands of 'unbound-control' create a bare local zones tree for an already configured named view when the view is configured with no local data to begin with. However, the creation through the control interface omits adding the default-protected zones (e.g., RFC 1918 reverse, AS112 zones, .onion, .localhost). Once the local zone tree exists without the defaults, every query for a default-protected name from a client mapped to that view escapes to the public DNS via the iterator instead of being answered locally, bypassing local policy expectations.

• CWE-1188Initialization of a Resource with an Insecure DefaultThe product initializes or sets a resource with a default that is intended to be changed by the product's installer, administrator, or maintainer, but the default is not secure.