{"id":"CVE-2026-4891","title":"A heap-based out-of-bounds read vulnerability in the DNSSEC validation of dnsmasq allows remote attackers to cause a denial of service via a crafted DNS packet.","summary":"A heap-based out-of-bounds read vulnerability in the DNSSEC validation of dnsmasq allows remote attackers to cause a denial of service via a crafted DNS packet.","severity":"medium","cvss":5.3,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","cwe":["CWE-125"],"published":"2026-05-11","updated":"2026-07-02","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-4891","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-2026-4891","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2458517","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-4891.json","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"}],"tags":["nvd"],"epss":0.06411,"epssPercentile":0.93377,"ingestedAt":"2026-07-02T13:35:59.397Z","slug":"CVE-2026-4891","body":"## Overview\n\nA heap-based out-of-bounds read vulnerability in the DNSSEC validation of dnsmasq allows remote attackers to cause a denial of service via a crafted DNS packet.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":29.2,"likelihood":1.3,"exploitation":0,"ransomware":0},"changes":[]}