{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-80905",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2026-08-26T14:34:25.800Z",
        "datePublished": "2026-09-04T17:19:15.289Z",
        "dateUpdated": "2026-10-21T12:47:13.437Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-10-21T12:47:13.437Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: tap: fix wrong transport_header when sending VLAN-tagged frame\n\nIn tap_get_user_xdp(), when processing a VLAN-tagged frame (e.g.\nETH_P_8021Q), skb_set_network_header() is called first to advance\nnetwork_header past the VLAN tag to the inner protocol header.\nskb_probe_transport_header() is then called with skb->protocol still\nset to ETH_P_8021Q, while nhoff (derived from skb_network_offset())\nalready points past the VLAN tag to the inner protocol header.\n\nIn __skb_flow_dissect(), proto is initialized to ETH_P_8021Q and nhoff\npoints past the VLAN tag. When the dissector hits case ETH_P_8021Q, it\nreads a struct vlan_hdr at the current nhoff via __skb_header_pointer(),\nbut that offset contains the inner protocol header (e.g. an IP header).\nThe bytes are misinterpreted as a VLAN header, yielding a garbage\nencapsulated EtherType that matches no known protocol. The dissector\nreturns false, so skb_probe_transport_header() never calls\nskb_set_transport_header(), leaving transport_header at its uninitialized\nsentinel value (~0U).\n\nMove skb_set_network_header() to after skb_probe_transport_header(). At\nthe time skb_probe_transport_header() is called, network_header still\npoints to the VLAN header (offset ETH_HLEN), so nhoff is correct and the\nflow dissector can parse the VLAN header, extract the inner EtherType,\nand advance nhoff to the inner protocol header, allowing transport_header\nto be set correctly."
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "drivers/net/tap.c"
                    ],
                    "versions": [
                        {
                            "version": "8c76e77f9069f10505c08e02646c3ee11ad79038",
                            "lessThan": "c0376820922d255ae1d103c32345a6ec4c3266f7",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "8c76e77f9069f10505c08e02646c3ee11ad79038",
                            "lessThan": "f1d297cad5c1eacd9fadfd0346ad97405ffbf97c",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "8c76e77f9069f10505c08e02646c3ee11ad79038",
                            "lessThan": "5ffaa5d7f56ab24a8e23cf131eadfef31a3bbc4b",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "8c76e77f9069f10505c08e02646c3ee11ad79038",
                            "lessThan": "88b79ac89ecc04d7f2613f7e1c0b46f0c4ddb2f3",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "8c76e77f9069f10505c08e02646c3ee11ad79038",
                            "lessThan": "cbb35cbe8db268fefe34c23df15348cf99025298",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "3cae5ef1f37a475faf7c40bc6a3c170779f3e0b1",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "4.20.1",
                            "lessThan": "4.21",
                            "status": "affected",
                            "versionType": "semver"
                        }
                    ]
                },
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "affected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "drivers/net/tap.c"
                    ],
                    "versions": [
                        {
                            "version": "5.0",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "5.0",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.6.160",
                            "lessThanOrEqual": "6.6.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.12.114",
                            "lessThanOrEqual": "6.12.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.18.46",
                            "lessThanOrEqual": "6.18.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.1.10",
                            "lessThanOrEqual": "7.1.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.2",
                            "lessThanOrEqual": "*",
                            "status": "unaffected",
                            "versionType": "original_commit_for_fix"
                        }
                    ]
                }
            ],
            "cpeApplicability": [
                {
                    "nodes": [
                        {
                            "operator": "OR",
                            "negate": false,
                            "cpeMatch": [
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "5.0",
                                    "versionEndExcluding": "6.6.160"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "5.0",
                                    "versionEndExcluding": "6.12.114"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "5.0",
                                    "versionEndExcluding": "6.18.46"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "5.0",
                                    "versionEndExcluding": "7.1.10"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "5.0",
                                    "versionEndExcluding": "7.2"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "4.20.1"
                                }
                            ]
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/c0376820922d255ae1d103c32345a6ec4c3266f7"
                },
                {
                    "url": "https://git.kernel.org/stable/c/f1d297cad5c1eacd9fadfd0346ad97405ffbf97c"
                },
                {
                    "url": "https://git.kernel.org/stable/c/5ffaa5d7f56ab24a8e23cf131eadfef31a3bbc4b"
                },
                {
                    "url": "https://git.kernel.org/stable/c/88b79ac89ecc04d7f2613f7e1c0b46f0c4ddb2f3"
                },
                {
                    "url": "https://git.kernel.org/stable/c/cbb35cbe8db268fefe34c23df15348cf99025298"
                }
            ],
            "title": "net: tap: fix wrong transport_header when sending VLAN-tagged frame",
            "x_generator": {
                "engine": "bippy-1.2.0"
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    }
}