{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-97206", "assignerOrgId": "206fc3a0-e175-490b-9eaa-a5738056c9f6", "state": "PUBLISHED", "assignerShortName": "NLnet Labs", "dateReserved": "2026-10-14T09:16:14.090Z", "datePublished": "2026-10-21T08:57:41.106Z", "dateUpdated": "2026-10-21T08:57:41.106Z"}, "containers": {"cna": {"title": "DNS-over-QUIC (DoQ) path-migration can lead to use-after-free on multi-threaded deployments.", "datePublic": "2026-10-21T00:00:00.000Z", "affected": [{"vendor": "NLnet Labs", "product": "Unbound", "versions": [{"version": "1.22.0", "status": "affected", "lessThan": "1.26.2", "versionType": "semver"}], "defaultStatus": "unaffected"}], "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."}], "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": [{"lang": "en", "cweId": "CWE-416", "description": "CWE-416: Use After Free", "type": "CWE"}]}], "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"}], "references": [{"url": "https://www.nlnetlabs.nl/downloads/unbound/CVE-2026-97206.txt", "tags": ["vendor-advisory"]}], "providerMetadata": {"orgId": "206fc3a0-e175-490b-9eaa-a5738056c9f6", "shortName": "NLnet Labs", "dateUpdated": "2026-10-21T08:57:41.106Z"}, "x_generator": {"engine": "cvelib 1.8.0"}}}}

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{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Unbound", "vendor": "NLnet Labs", "versions": [{"lessThan": "1.26.2", "status": "affected", "version": "1.22.0", "versionType": "semver"}]}], "source": "sep@nlnetlabs.nl"}], "cveTags": [], "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."}], "id": "CVE-2026-97206", "lastModified": "2026-10-21T09:17:08.473", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 7.5, "baseSeverity": "HIGH", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 3.6, "source": "sep@nlnetlabs.nl", "type": "Secondary"}]}, "published": "2026-10-21T09:17:08.473", "references": [{"source": "sep@nlnetlabs.nl", "url": "https://www.nlnetlabs.nl/downloads/unbound/CVE-2026-97206.txt"}], "sourceIdentifier": "sep@nlnetlabs.nl", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-416"}], "source": "sep@nlnetlabs.nl", "type": "Secondary"}]}

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