VDB
CVE-2026-50106
CVE-2026-50106
PUBLISHED
CVSS 6.5 MEDIUM
Reported by NLnet Labs · Published October 21, 2026
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.
Risk Scores
CVSS 3.1
6.5
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| NLnet Labs | Unbound | 0 |
| amazon:2023 | unbound-devel | 0 |
| alpine | unbound | 0 |
| amazon:2023 | unbound | 0 |
| amazon:2023 | unbound-anchor | 0 |
| amazon:2023 | unbound-libs | 0 |
| NLnet Labs | Unbound | 0 |
| amazon:2023 | python3-unbound | 0 |
| amazon:2023 | unbound-utils | 0 |
Timeline
- Oct 21, 2026 EPSS Score
- Oct 21, 2026 CVE Published
- Oct 25, 2026 EPSS Score
- Oct 29, 2026 EPSS Score