vuln-cve/data/2026/12xxx/CVE-2026-12708.json

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    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-12708",
        "assignerOrgId": "a22f1246-ba21-4bb4-a601-ad51614c1513",
        "state": "PUBLISHED",
        "assignerShortName": "cloudflare",
        "dateReserved": "2026-06-19T10:44:16.225Z",
        "datePublished": "2026-11-10T13:25:09.558Z",
        "dateUpdated": "2026-11-10T13:42:52.186Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "a22f1246-ba21-4bb4-a601-ad51614c1513",
                "shortName": "cloudflare",
                "dateUpdated": "2026-11-10T13:42:52.186Z"
            },
            "title": "Unbounded HTTP/3 Datagram flow map growth in tokio-quiche",
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "lang": "en",
                            "cweId": "CWE-401",
                            "description": "CWE-401 Missing release of memory after effective lifetime",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "impacts": [
                {
                    "capecId": "CAPEC-130",
                    "descriptions": [
                        {
                            "lang": "en",
                            "value": "CAPEC-130 Excessive Allocation"
                        }
                    ]
                }
            ],
            "affected": [
                {
                    "vendor": "Cloudflare",
                    "product": "tokio-quiche",
                    "repo": "https://github.com/cloudflare/quiche/tree/master/tokio-quiche",
                    "versions": [
                        {
                            "status": "affected",
                            "version": "0.0.1",
                            "lessThanOrEqual": "0.20.1",
                            "versionType": "semver"
                        }
                    ],
                    "defaultStatus": "unaffected"
                }
            ],
            "descriptions": [
                {
                    "lang": "en",
                    "value": "Summary\n\n\nCloudflare tokio-quiche was found to contain an uncontrolled resource consumption vulnerability in its HTTP/3 DATAGRAM handling. For every previously unseen flow identifier (quarter stream ID) received in a DATAGRAM frame, tokio-quiche creates and retains new, per-flow state. A remote peer can send DATAGRAMs with many distinct identifiers, causing the per-connection flow map and associated channel state to grow without bound.\n\nImpact\n\n\nExploitation can exhaust process memory and cause a denial of service. The vulnerable code is used in both client and server configurations, so either role can be affected by a malicious peer. QUIC DATAGRAM support in tokio-quiche is enabled by default through QuicSettings::enable_dgram; applications can disable it by setting this field to false. The vulnerable HTTP/3 path is reachable only when DATAGRAM support is negotiated with the peer. Core quiche and HTTP/3 deployments without DATAGRAM support are not affected. \n\n\n\n\n\n\nMitigation\n\n\nDisable DATAGRAMs in tokio-quiche’s QuicSettings::enable_dgram.\n\n\n\n\n\n\nRemediation\n\n\nUpgrade to tokio-quiche version 0.23.0 or later. The fixed code creates flow state only for valid DATAGRAM-capable request streams, which are bounded by QUIC’s stream limits. To tolerate packet reordering, servers retain early DATAGRAMs in a bounded, expiring buffer, while clients discard DATAGRAMs for unknown flows.",
                    "supportingMedia": [
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                            "type": "text/html",
                            "base64": false,
                            "value": "<h2><b>Summary</b></h2><p><b><br></b><span>Cloudflare tokio-quiche was found to contain an uncontrolled resource consumption vulnerability in its HTTP/3 DATAGRAM handling. For every previously unseen flow identifier (quarter stream ID) received in a DATAGRAM frame, tokio-quiche creates and retains new, per-flow state. A remote peer can send DATAGRAMs with many distinct identifiers, causing the per-connection flow map and associated channel state to grow without bound.</span></p><h2><b>Impact</b></h2><p><b><br></b><span>Exploitation can exhaust process memory and cause a denial of service. The vulnerable code is used in both client and server configurations, so either role can be affected by a malicious peer. QUIC DATAGRAM support in tokio-quiche is enabled by default through </span><span>QuicSettings::enable_dgram</span><span>; applications can disable it by setting this field to </span><span>false</span><span>. The vulnerable HTTP/3 path is reachable only when DATAGRAM support is negotiated with the peer. Core quiche and HTTP/3 deployments without DATAGRAM support are not affected.&nbsp;</span></p><p><span><br></span></p><h2><b>Mitigation</b></h2><p><b><br></b><span>Disable DATAGRAMs in tokio-quiche’s </span><span>QuicSettings::enable_dgram</span><span>.</span></p><p><b><br></b></p><h2><b>Remediation</b></h2><p><b><br></b><span>Upgrade to tokio-quiche version 0.23.0 or later. The fixed code creates flow state only for valid DATAGRAM-capable request streams, which are bounded by QUIC’s stream limits. To tolerate packet reordering, servers retain early DATAGRAMs in a bounded, expiring buffer, while clients discard DATAGRAMs for unknown flows.</span></p><br>"
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://www.cve.org/CVERecord?id=CVE-2026-12708"
                },
                {
                    "url": "https://github.com/cloudflare/quiche/security/advisories/GHSA-wcm9-jv39-r963"
                }
            ],
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                    "format": "CVSS",
                    "scenarios": [
                        {
                            "lang": "en",
                            "value": "GENERAL"
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                    "cvssV4_0": {
                        "attackVector": "NETWORK",
                        "attackComplexity": "LOW",
                        "attackRequirements": "NONE",
                        "privilegesRequired": "NONE",
                        "userInteraction": "NONE",
                        "vulnConfidentialityImpact": "NONE",
                        "subConfidentialityImpact": "NONE",
                        "vulnIntegrityImpact": "NONE",
                        "subIntegrityImpact": "NONE",
                        "vulnAvailabilityImpact": "HIGH",
                        "subAvailabilityImpact": "NONE",
                        "exploitMaturity": "NOT_DEFINED",
                        "Safety": "NOT_DEFINED",
                        "Automatable": "NOT_DEFINED",
                        "Recovery": "NOT_DEFINED",
                        "valueDensity": "NOT_DEFINED",
                        "vulnerabilityResponseEffort": "NOT_DEFINED",
                        "providerUrgency": "NOT_DEFINED",
                        "version": "4.0",
                        "baseSeverity": "HIGH",
                        "baseScore": 8.7,
                        "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N"
                    }
                }
            ],
            "source": {
                "discovery": "UNKNOWN"
            },
            "x_generator": {
                "engine": "Vulnogram 1.0.5"
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    }
}