---
id: CVE-2026-4890
title: >-
  A Denial of Service (DoS) vulnerability in the DNSSEC validation of dnsmasq
  allows remote attackers to cause a denial of service via a crafted DNS packet.
summary: >-
  A Denial of Service (DoS) vulnerability in the DNSSEC validation of dnsmasq
  allows remote attackers to cause a denial of service via a crafted DNS packet.
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-835
published: '2026-05-11'
updated: '2026-07-02'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-4890'
references:
  - url: 'https://github.com/NixOS/nixpkgs/pull/519082'
    label: cret@cert.org
  - url: 'https://github.com/NixOS/nixpkgs/pull/519093'
    label: cret@cert.org
  - url: 'https://github.com/pi-hole/FTL/releases/tag/v6.6.2'
    label: cret@cert.org
  - url: >-
      https://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2026q2/018471.html
    label: cret@cert.org
  - url: 'https://thekelleys.org.uk/dnsmasq/CVE/'
    label: cret@cert.org
  - url: 'https://www.kb.cert.org/vuls/id/471747'
    label: cret@cert.org
  - url: 'https://access.redhat.com/errata/RHSA-2026:19158'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:19373'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:20589'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:34508'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/security/cve/CVE-2026-4890'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2458516'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-4890.json
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-4890'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-4890'
  - url: 'https://access.redhat.com/errata/RHSA-2026:40762'
tags:
  - nvd
  - csaf
  - vex
  - red-hat
epss: 0.08849
epssPercentile: 0.95175
ingestedAt: '2026-07-02T13:35:59.386Z'
vendor: Red Hat
product: Red Hat Enterprise Linux AppStream (v. 10)
affected:
  - enterprise_linux 6
  - enterprise_linux 7
  - openshift_container_platform 4
  - openshift_container_platform 4.19
  - enterprise_linux_appstream_v_10
  - enterprise_linux_appstream_v_8
  - enterprise_linux_appstream_eus_v_9_6
  - enterprise_linux_appstream_v_9
patched:
  - openshift_container_platform 4.19
  - enterprise_linux_appstream_v_10
  - enterprise_linux_appstream_v_8
  - enterprise_linux_appstream_eus_v_9_6
  - enterprise_linux_appstream_v_9
---

## Overview

A Denial of Service (DoS) vulnerability in the DNSSEC validation of dnsmasq allows remote attackers to cause a denial of service via a crafted DNS packet.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Vendor advisories

- **RHSA-2026:40762** · Red Hat · fixed in: Red Hat OpenShift Container Platform 4.19 · released 2026-07-22 · [advisory](https://access.redhat.com/errata/RHSA-2026:40762)
- **RHSA-2026:19158** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 10) · released 2026-05-19 · [advisory](https://access.redhat.com/errata/RHSA-2026:19158)
- **RHSA-2026:20589** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 8) · released 2026-05-26 · [advisory](https://access.redhat.com/errata/RHSA-2026:20589)
- **RHSA-2026:34508** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream EUS (v.9.6) · released 2026-07-01 · [advisory](https://access.redhat.com/errata/RHSA-2026:34508)
- **RHSA-2026:19373** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 9) · released 2026-05-19 · [advisory](https://access.redhat.com/errata/RHSA-2026:19373)
- **Red Hat VEX** · Important · affected: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7 · updated 2026-10-16 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-4890.json)