{"id":"CVE-2026-97206","title":"DNS-over-QUIC (DoQ) path-migration can lead to use-after-free on multi-threaded deployments.","summary":"NLnet Labs Unbound, 1.22.0 up to and including version 1.26.1, contains a DNS-over-QUIC (DoQ) lifetime bug reachable by a remote DoQ client under multi-threaded operation. A client-triggered QUIC path migration can enter stream/connectio…","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-416"],"vendor":"NLnet Labs","product":"Unbound","affected":["Unbound >= 1.22.0 < 1.26.2"],"published":"2026-10-21","updated":"2026-10-21","sourceUpdated":"2026-10-21T08:57:41.106Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-97206","references":[{"url":"https://www.nlnetlabs.nl/downloads/unbound/CVE-2026-97206.txt"}],"tags":["cve.org"],"ingestedAt":"2026-10-21T09:46:15.395Z","slug":"CVE-2026-97206","body":"## Overview\n\nNLnet Labs Unbound, 1.22.0 up to and including version 1.26.1, contains a DNS-over-QUIC (DoQ) lifetime bug reachable by a remote DoQ client under multi-threaded operation. A client-triggered QUIC path migration can enter stream/connection cleanup while a mesh reply still retains a pointer to the DoQ stream. Cleanup frees the DoQ stream and when the pending mesh reply later completes it dereferences a stale pointer leading to a crash.\n\n## Affected\n\n- `Unbound >= 1.22.0 < 1.26.2`\n\n## Remediation\n\nThis issue is fixed starting with version 1.26.2","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}