# CVE-2026-123596: rust-hickory-net: Hickory DNS hickory-proto through 0.26.0-alpha.1 and hickory-net 0.26.0-beta.1 before 0.26.2 contain a DNSSEC validat...

CVE-2026-123596 is fixed in rust-hickory-net on 1 platform by DEBIAN-CVE-2026-123596 (version 0.26.3-1), released November 9, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-123596
- Priority: High
- CVSS: 8.8 (high)
- EPSS: 0.0019
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Nov 8, 2026

## Description

Hickory DNS hickory-proto through 0.26.0-alpha.1 and hickory-net 0.26.0-beta.1 before 0.26.2 contain a DNSSEC validation flaw in the validating recursor's NSEC handler that accepts parent-side ancestor-delegation NSEC records as proof of nonexistence for names below the zone cut. An on-path attacker, rogue parent nameserver, or attacker winning a port and TXID race can deliver one forged NXDOMAIN response built from genuinely signed parent NSEC records, causing authenticated denial of existing child-zone names cached for the negative TTL.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | rust-hickory-net Debian 14 | 0.26.3-1 | [DEBIAN-CVE-2026-123596](https://patchblox.com/security/data/fix/linux/debian-cve-2026-123596.md) | Nov 9, 2026 |

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Data as of 2026-11-11T01:43:54Z 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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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