---
id: "CVE-2026-123577"
page: "https://infrastack.ai/live/CVE-2026-123577"
kind: "vulnerability"
aliases: ["CVE-2026-123577"]
title: "Hickory DNS: unbounded DoH request bodies let remote attackers exhaust memory"
severity: "high"
cvss: 8.7
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["dns-over-https", "hickory-dns", "package", "rust", "self-hosted"]
not_affected_if: ["no-doh-listener", "udp-tcp-dns-only", "version-0.26.2-or-later"]
published_at: "2026-11-08T02:16:51+00:00"
first_seen_at: "2026-11-08T02:21:12+00:00"
updated_at: "2026-11-08T02:22:52+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-123577", "first_seen_at": "2026-11-08T02:21:12+00:00"}]
exploit_sources: []
---

# Hickory DNS: unbounded DoH request bodies let remote attackers exhaust memory

Link for people: https://infrastack.ai/live/CVE-2026-123577 (this .md is for agents)

Hickory DNS, a Rust DNS server and library, does not limit the size of DNS-over-HTTPS request bodies. A remote attacker can send very large request bodies over HTTP/2 or HTTP/3 to exhaust server memory and cause a denial of service.

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

## How to check

- Check the Hickory DNS version in your `Cargo.lock` or dependency tree (for example `cargo tree -p hickory-server`).
- Confirm whether DNS-over-HTTPS (DoH) is enabled on your server.

## Fix

- Hickory DNS: move to `0.26.2` or later.

## Timeline

- 2026-11-08T02:21:12+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-123577

## Documents

- [advisory] Vendor advisory: github.com https://github.com/hickory-dns/hickory-dns/security/advisories/GHSA-5r56-v84h-c3w5
- [advisory] Third-party advisory: www.vulncheck.com https://www.vulncheck.com/advisories/hickory-dns-0.24.0-before-0.26.2-doh-unbounded-request-body-denial-of-service

## From the sources

Hickory DNS from 0.24.0 before 0.26.2 contains a resource exhaustion vulnerability that allows remote attackers to consume server memory via unbounded DoH request bodies. Attackers can send large request bodies over HTTP/2 or HTTP/3 to a DNS over HTTP server, causing memory exhaustion and denial of service.

---

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