# CVE-2026-50106: unbound: When NLnet Labs Unbound up to and including version 1.26.1 is configured with both a root trust anchor and an additio...

CVE-2026-50106 is fixed in 12 products on 1 platform, first by DEBIAN-CVE-2026-50106, released October 24, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-50106
- Priority: Routine
- CVSS: 6.5 (medium)
- EPSS: 0.0021
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Oct 21, 2026

## Description

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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | python3-unbound amzn 2023 | 1.17.1-1.amzn2023.0.17 | [ALAS2023-2026-3313](https://patchblox.com/security/data/fix/linux/alas2023-2026-3313.md) | Nov 7, 2026 |
| Linux | python3-unbound-debuginfo amzn 2023 | 1.17.1-1.amzn2023.0.17 | [ALAS2023-2026-3313](https://patchblox.com/security/data/fix/linux/alas2023-2026-3313.md) | Nov 7, 2026 |
| Linux | unbound Debian 13.5 (trixie) | 1.26.2-0+deb13u1 | [DEBIAN-CVE-2026-50106](https://patchblox.com/security/data/fix/linux/debian-cve-2026-50106.md) | Oct 24, 2026 |
| Linux | unbound Debian 14 | 1.26.2-1 | [DEBIAN-CVE-2026-50106](https://patchblox.com/security/data/fix/linux/debian-cve-2026-50106.md) | Oct 24, 2026 |
| Linux | unbound amzn 2023 | 1.17.1-1.amzn2023.0.17 | [ALAS2023-2026-3313](https://patchblox.com/security/data/fix/linux/alas2023-2026-3313.md) | Nov 7, 2026 |
| Linux | unbound-anchor amzn 2023 | 1.17.1-1.amzn2023.0.17 | [ALAS2023-2026-3313](https://patchblox.com/security/data/fix/linux/alas2023-2026-3313.md) | Nov 7, 2026 |
| Linux | unbound-anchor-debuginfo amzn 2023 | 1.17.1-1.amzn2023.0.17 | [ALAS2023-2026-3313](https://patchblox.com/security/data/fix/linux/alas2023-2026-3313.md) | Nov 7, 2026 |
| Linux | unbound-debuginfo amzn 2023 | 1.17.1-1.amzn2023.0.17 | [ALAS2023-2026-3313](https://patchblox.com/security/data/fix/linux/alas2023-2026-3313.md) | Nov 7, 2026 |
| Linux | unbound-debugsource amzn 2023 | 1.17.1-1.amzn2023.0.17 | [ALAS2023-2026-3313](https://patchblox.com/security/data/fix/linux/alas2023-2026-3313.md) | Nov 7, 2026 |
| Linux | unbound-devel amzn 2023 | 1.17.1-1.amzn2023.0.17 | [ALAS2023-2026-3313](https://patchblox.com/security/data/fix/linux/alas2023-2026-3313.md) | Nov 7, 2026 |
| Linux | unbound-libs amzn 2023 | 1.17.1-1.amzn2023.0.17 | [ALAS2023-2026-3313](https://patchblox.com/security/data/fix/linux/alas2023-2026-3313.md) | Nov 7, 2026 |
| Linux | unbound-libs-debuginfo amzn 2023 | 1.17.1-1.amzn2023.0.17 | [ALAS2023-2026-3313](https://patchblox.com/security/data/fix/linux/alas2023-2026-3313.md) | Nov 7, 2026 |
| Linux | unbound-utils amzn 2023 | 1.17.1-1.amzn2023.0.17 | [ALAS2023-2026-3313](https://patchblox.com/security/data/fix/linux/alas2023-2026-3313.md) | Nov 7, 2026 |
| Linux | unbound-utils-debuginfo amzn 2023 | 1.17.1-1.amzn2023.0.17 | [ALAS2023-2026-3313](https://patchblox.com/security/data/fix/linux/alas2023-2026-3313.md) | Nov 7, 2026 |

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Data as of 2026-11-08T06:59:42Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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