{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-32665","assignerOrgId":"206fc3a0-e175-490b-9eaa-a5738056c9f6","state":"PUBLISHED","assignerShortName":"NLnet Labs","dateReserved":"2026-05-07T10:07:51.860Z","datePublished":"2026-07-22T13:04:18.594Z","dateUpdated":"2026-07-22T14:32:02.752Z"},"containers":{"cna":{"title":"Remote DNS-over-QUIC denial of service due to `quic-size` budget bypass","datePublic":"2026-07-22T00:00:00.000Z","affected":[{"vendor":"NLnet Labs","product":"Unbound","versions":[{"version":"1.22.0","status":"affected","lessThan":"1.25.2","versionType":"semver"}],"defaultStatus":"unaffected"}],"descriptions":[{"lang":"en","value":"In NLnet Labs Unbound 1.22.0 up to and including 1.25.1, when downstream DNS-over-QUIC (DoQ) is enabled, the first two bidirectional streams on a new QUIC connection (stream_id 0 and 4) bypass the per-stream 'quic-size' gate entirely, and large input buffers are allocated later, after only the 2-byte length prefix has been received from the initial streams. As a result, a remote client can make Unbound exceed the configured 'quic-size' limit with low-cost input. Using only one connection and two streams, each sending a declared 65535-byte length prefix and then holding the streams open, a client can already trivially make Unbound roughly allocate double that amount. This is a remote availability issue / memory-accounting bypass in the downstream DoQ implementation that leads to denial of service for new DoQ clients. This vulnerability needs Unbound to be compiled with DoQ support ('--with-libngtcp2') and the 'quic-port' to be configured for the listening interfaces."}],"metrics":[{"format":"CVSS","scenarios":[{"lang":"en","value":"Unbound compiled with DoQ support ('--with-libngtcp2')"}],"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-1284","description":"CWE-1284: Improper Validation of Specified Quantity in Input","type":"CWE"}]}],"solutions":[{"lang":"en","value":"This issue is fixed starting with version 1.25.2"}],"timeline":[{"time":"2026-04-01T00:00:00.000Z","lang":"en","value":"Issue reported by N0zoM1z0"},{"time":"2026-04-03T00:00:00.000Z","lang":"en","value":"NLnet Labs shares patch with N0zoM1z0"},{"time":"2026-04-03T00:00:00.000Z","lang":"en","value":"N0zoM1z0 verifies patch"},{"time":"2026-04-03T00:00:00.000Z","lang":"en","value":"Issue reported by Kunta Chu"},{"time":"2026-04-09T00:00:00.000Z","lang":"en","value":"NLnet Labs shares patch with Kunta Chu"},{"time":"2026-04-03T00:00:00.000Z","lang":"en","value":"Kunta Chu verifies patch"},{"time":"2026-05-30T00:00:00.000Z","lang":"en","value":"Issue reported by Qifan Zhang"},{"time":"2026-06-15T00:00:00.000Z","lang":"en","value":"NLnet Labs shares patch with Qifan Zhang"},{"time":"2026-06-17T00:00:00.000Z","lang":"en","value":"Qifan Zhang verifies patch"},{"time":"2026-07-10T00:00:00.000Z","lang":"en","value":"Issue reported by Xuanchao Xie"},{"time":"2026-07-10T00:00:00.000Z","lang":"en","value":"NLnet Labs shares patch with Xuanchao Xie"},{"time":"2026-07-11T00:00:00.000Z","lang":"en","value":"Xuanchao Xie verifies patch"},{"time":"2026-07-22T00:00:00.000Z","lang":"en","value":"Fixes released with version 1.25.2"}],"credits":[{"lang":"en","value":"N0zoM1z0 (GitHub user)","type":"finder"},{"lang":"en","value":"Kunta Chu (Tsinghua University)","type":"finder"},{"lang":"en","value":"Kaihua Wang (Tsinghua University)","type":"finder"},{"lang":"en","value":"Jianjun Chen (Tsinghua University)","type":"finder"},{"lang":"en","value":"Qifan Zhang (Palo Alto Networks)","type":"finder"},{"lang":"en","value":"Xuanchao Xie","type":"finder"}],"references":[{"url":"https://www.nlnetlabs.nl/downloads/unbound/CVE-2026-32665.txt","tags":["vendor-advisory"]}],"providerMetadata":{"orgId":"206fc3a0-e175-490b-9eaa-a5738056c9f6","shortName":"NLnet Labs","dateUpdated":"2026-07-22T13:04:18.594Z"},"x_generator":{"engine":"cvelib 1.8.0"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-07-22T14:31:54.691586Z","id":"CVE-2026-32665","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-07-22T14:32:02.752Z"}}]}}