{"id":"CVE-2026-123570","title":"Hickory DNS from 0.18 before 0.26.2 Memory Amplification DoS via RR Counts","summary":"The DNS wire-format message parser in hickory-proto (Hickory DNS) 0.18 before 0.26.2 preallocates record vectors sized by the untrusted ANCOUNT, NSCOUNT, and ARCOUNT header fields before reading record data. Remote attackers can send a U…","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","cvssSource":"cna","cwe":["CWE-400"],"vendor":"hickory-dns","product":"hickory-dns","affected":["hickory-dns >= 0.18 < 0.26.2"],"published":"2026-11-08","updated":"2026-11-08","sourceUpdated":"2026-11-08T01:38:07.919Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-123570","references":[{"url":"https://github.com/hickory-dns/hickory-dns/security/advisories/GHSA-67wc-6jq8-ghrc","label":"GitHub Security Advisory (GHSA-67wc-6jq8-ghrc)"},{"url":"https://www.vulncheck.com/advisories/hickory-dns-from-0.18-before-0.26.2-memory-amplification-dos-via-rr-counts","label":"VulnCheck Advisory: Hickory DNS from 0.18 before 0.26.2 Memory Amplification DoS via RR Counts"}],"tags":["cve.org"],"ingestedAt":"2026-11-08T02:43:18.657Z","slug":"CVE-2026-123570","body":"## Overview\n\nThe DNS wire-format message parser in hickory-proto (Hickory DNS) 0.18 before 0.26.2 preallocates record vectors sized by the untrusted ANCOUNT, NSCOUNT, and ARCOUNT header fields before reading record data. Remote attackers can send a UDP datagram, or a spoofed response to a client/resolver, with these counts set to 65535, forcing about 18MB of allocation per message.\n\n## Affected\n\n- `hickory-dns >= 0.18 < 0.26.2`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}