---
id: "CVE-2026-93011"
kind: "vulnerability"
aliases: ["CVE-2026-93011"]
title: "dnsmasq: DNSSEC validator can overwrite adjacent heap memory"
severity: "medium"
cvss: 5.3
epss: null
exploited: false
status: "open"
category: "infrastructure"
products: []
ecosystems: []
tags: ["dns-resolver", "dnsmasq", "infrastructure", "linux", "self-hosted"]
not_affected_if: ["default-config", "dnssec-disabled"]
published_at: "2026-10-29T13:17:16+00:00"
first_seen_at: "2026-10-29T13:25:08+00:00"
updated_at: "2026-10-29T13:25:47+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-93011", "first_seen_at": "2026-10-29T13:25:08+00:00"}]
---

# dnsmasq: DNSSEC validator can overwrite adjacent heap memory

dnsmasq's DNSSEC validator can write a few bytes past a name buffer when converting domain names to and from DNS wire format. An attacker who gets the server to validate a crafted DNSSEC response may corrupt small amounts of adjacent heap metadata.

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

## How to check

- Check whether DNSSEC support is compiled in and enabled at runtime; the sources say it is off by default and needs both.
- Check the installed dnsmasq version with `dnsmasq --version` against the affected range; the sources do not give the range.

## Timeline

- 2026-10-29T13:25:08+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-93011

## From the sources

A flaw was found in dnsmasq. After a reduction of internal domain-name buffer sizes, the DNSSEC validator can write a few bytes past a name buffer when converting names to and from DNS wire format. An attacker who can cause the server to validate a crafted DNSSEC response may overwrite a small amount of adjacent heap metadata. DNSSEC support is not compiled in by default and must also be enabled at runtime.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_