{"id":"CVE-2026-97206","state":"PUBLISHED","title":"DNS-over-QUIC (DoQ) path-migration can lead to use-after-free on multi-threaded deployments.","description":"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/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.","publishedAt":"2026-10-21T08:57:41.106Z","updatedAt":"2026-10-29T19:08:32.470Z","severity":{"score":7.5,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","source":"NLnet Labs"},"assigner":"NLnet Labs","products":["NLnet Labs Unbound"],"affected":[{"vendor":"NLnet Labs","product":"Unbound","defaultStatus":"unaffected","versions":[{"version":"1.22.0","status":"affected","lessThan":"1.26.2","versionType":"semver"}]}],"references":["https://www.nlnetlabs.nl/downloads/unbound/CVE-2026-97206.txt"],"weaknesses":["CWE-416"],"ingestedAt":"2026-10-29T20:13:43.249Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/97xxx/CVE-2026-97206.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-97206","state":"PUBLISHED","datePublished":"2026-10-21T08:57:41.106Z","dateUpdated":"2026-10-29T19:08:32.470Z","assignerShortName":"NLnet Labs","assignerOrgId":"206fc3a0-e175-490b-9eaa-a5738056c9f6","dateReserved":"2026-10-14T09:16:14.090Z"},"containers":{"cna":{"title":"DNS-over-QUIC (DoQ) path-migration can lead to use-after-free on multi-threaded deployments.","descriptions":[{"lang":"en","value":"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/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."}],"affected":[{"vendor":"NLnet Labs","product":"Unbound","defaultStatus":"unaffected","versions":[{"version":"1.22.0","status":"affected","lessThan":"1.26.2","versionType":"semver"}]}],"references":[{"url":"https://www.nlnetlabs.nl/downloads/unbound/CVE-2026-97206.txt","tags":["vendor-advisory"]}],"metrics":[{"format":"CVSS","scenarios":[{"lang":"en","value":"compiled with DNS-over-QUIC support"}],"cvssV3_1":{"version":"3.1","baseScore":7.5,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-416","lang":"en","description":"CWE-416: Use After Free","type":"CWE"}]}],"providerMetadata":{"shortName":"NLnet Labs","orgId":"206fc3a0-e175-490b-9eaa-a5738056c9f6","dateUpdated":"2026-10-21T08:57:41.106Z"},"datePublic":"2026-10-21T00:00:00.000Z","solutions":[{"lang":"en","value":"This issue is fixed starting with version 1.26.2"}],"timeline":[{"time":"2026-09-20T00:00:00.000Z","lang":"en","value":"Issue reported by Kunta Chu"},{"time":"2026-09-29T00:00:00.000Z","lang":"en","value":"NLnet Labs shares patch"},{"time":"2026-09-30T00:00:00.000Z","lang":"en","value":"Kunta Chu verifies patch"},{"time":"2026-10-21T00:00:00.000Z","lang":"en","value":"Fixes released with version 1.26.2"}],"credits":[{"lang":"en","value":"Kunta Chu (Tsinghua University)","type":"finder"},{"lang":"en","value":"Jianjun Chen (Tsinghua University)","type":"finder"}],"x_generator":{"engine":"cvelib 1.8.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-10-29T19:08:11.587798Z","id":"CVE-2026-97206","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-29T19:08:32.470Z"}}]}}}