CVE-2026-50106
Fixed in a distro release EPSS <1%CVSS 6.5
When NLnet Labs Unbound up to and including version 1.26.1 is configured with both a root trust anchor and an additional 'trust-anchor:' for an island-of-security zone whose parent is provably insecure under the root chain, a malicious actor who can deliver one forged NXDOMAIN response for a name inside the island, with the NSEC/SOA RRSIG 'SignerName' set to the insecure parent, tricks Unbound's validator to use the root trust anchor instead, and consecutively the insecure parent, thus causing that record to be treated as insecure and denying existence for records in the trust island.
Products: NLnet Labs unbound
Distro releases
| Release | Package | Fixed in |
|---|---|---|
| Amazon Linux 2023 | python3-unbound | 1.17.1-1.amzn2023.0.17 |
| Amazon Linux 2023 | unbound | 1.17.1-1.amzn2023.0.17 |
| Amazon Linux 2023 | unbound-anchor | 1.17.1-1.amzn2023.0.17 |
| Amazon Linux 2023 | unbound-devel | 1.17.1-1.amzn2023.0.17 |
| Amazon Linux 2023 | unbound-libs | 1.17.1-1.amzn2023.0.17 |
| Amazon Linux 2023 | unbound-utils | 1.17.1-1.amzn2023.0.17 |
| Debian 12 | unbound | no fix |
| Debian 13 | unbound | 1.26.2-0+deb13u1 |
| Debian 14 | unbound | 1.26.2-1 |
| Ubuntu 22.04 LTS | unbound | no fix |
| Ubuntu 24.04 LTS | unbound | no fix |
| Ubuntu 26.04 LTS | unbound | no fix |
| Ubuntu 26.10 | unbound | no fix |
| Ubuntu Pro 14.04 LTS | unbound | no fix |
| Ubuntu Pro 16.04 LTS | unbound | no fix |
| Ubuntu Pro 18.04 LTS | unbound | no fix |
| Ubuntu Pro 20.04 LTS | unbound | no fix |
| openSUSE Tumbleweed | unbound | 1.26.2-1.1 |