CVE-2026-55708
LowCVSS 3.1Exploitation Probability (EPSS)
Low risk2th percentile - higher than 2% of all known CVEs
Summary
In Unbound from version 1.6.0 up to 1.25.1, the 'view_local_data' and 'view_local_datas' commands in 'unbound-control' create a bare local zone tree for a view without default-protected zones (e.g., RFC 1918 reverse, AS112, .onion, .localhost). This causes queries for these names to be forwarded to public DNS instead of being answered locally, bypassing local policy.
Risk Assessment
The organization may lose control over DNS traffic for protected domains, potentially leading to data leakage or security policy violations.
Recommendation
It is recommended to manually add default-protected zones to each view configured via the control interface or update Unbound to a patched version.
Original NVD description (English source)
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.