{
    "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"
                }
            }
        ]
    }
}