---
id: "CVE-2026-123607"
page: "https://infrastack.ai/live/CVE-2026-123607"
kind: "vulnerability"
aliases: ["CVE-2026-123607"]
title: "Hickory DNS: crafted NSEC3 response can exhaust memory or crash resolver"
severity: "high"
cvss: 8.7
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["dns", "dnssec", "hickory-dns", "package", "rust"]
not_affected_if: ["no-dnssec-validation", "other-dns-handle"]
published_at: "2026-11-08T02:16:55+00:00"
first_seen_at: "2026-11-08T02:21:14+00:00"
updated_at: "2026-11-08T02:22:46+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-123607", "first_seen_at": "2026-11-08T02:21:14+00:00"}]
exploit_sources: []
---

# Hickory DNS: crafted NSEC3 response can exhaust memory or crash resolver

Link for people: https://infrastack.ai/live/CVE-2026-123607 (this .md is for agents)

Hickory DNS hickory-proto and hickory-net contain an unbounded loop in DNSSEC NSEC3 closest-encloser proof validation when the SOA owner is not an ancestor of the query name. An upstream attacker who returns a crafted NoData or NXDomain response with a cross-zone SOA record can crash debug builds or exhaust memory in release builds.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the version of hickory-proto or hickory-net in your `Cargo.lock`, looking for `0.25.0-alpha.3` through `0.25.2` in hickory-proto or anything below `0.26.1` in hickory-net.
- Check whether the resolver validates DNSSEC through `DnssecDnsHandle`.

## Fix

- hickory-net: move to `0.26.1` or later
- hickory-proto: move to a release newer than `0.25.2` (the sources do not name the exact fixed version for this branch)

## Timeline

- 2026-11-08T02:21:14+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-123607

## Documents

- [advisory] Vendor advisory: github.com https://github.com/hickory-dns/hickory-dns/security/advisories/GHSA-3v94-mw7p-v465
- [advisory] Third-party advisory: www.vulncheck.com https://www.vulncheck.com/advisories/hickory-dns-nsec3-closest-encloser-proof-unbounded-loop-denial-of-service

## From the sources

Hickory DNS hickory-proto 0.25.0-alpha.3 through 0.25.2 and hickory-net before 0.26.1 contain an unbounded loop vulnerability in DnssecDnsHandle NSEC3 closest-encloser proof validation when the SOA owner is not an ancestor of the QNAME. Upstream attackers can return NoData or NXDomain responses with a cross-zone SOA record to panic debug builds or exhaust memory in release builds.

---

_Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai_