{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-98287",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2026-09-25T10:25:14.336Z",
        "datePublished": "2026-10-06T08:45:47.998Z",
        "dateUpdated": "2026-10-19T09:16:58.585Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-10-19T09:16:58.585Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\npppoatm: ensure a writable skb header and linear data\n\nIn pppoatm_send(), LLC encapsulation checks whether there is sufficient\nheadroom for the 4-byte LLC header, but does not ensure that the skb header\nis writable.\n\nNormal transmit packets passing through ppp_start_xmit() have their header\nunshared via skb_cow_head(). However, packets can also reach pppoatm_send()\nvia PPP channel bridging (PPPIOCBRIDGECHAN) without going through\nppp_start_xmit().\n\nUse skb_cow_head() to ensure both sufficient headroom and a writable\nheader before pushing the LLC header.\n\nWhile at it:\n- Call pskb_may_pull(skb, 1) before inspecting skb->data[0] to prevent\n  out-of-bounds reads on zero-length or non-linear frames (e.g. from\n  bridging).\n- Defer SC_COMP_PROT protocol compression until after pppoatm_may_send()\n  succeeds. This eliminates the temporary skb allocation on admission failure\n  and completely removes the fragile \"undo\" heuristic at the nospace label,\n  avoiding any risk of reading uninitialized headroom or performing an\n  unbalanced skb_push()."
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "net/atm/pppoatm.c"
                    ],
                    "versions": [
                        {
                            "version": "4cf476ced45d7f12df30a68e833b263e7a2202d1",
                            "lessThan": "208ccc4d08b1897451e9ba01c016bf93ff107966",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "4cf476ced45d7f12df30a68e833b263e7a2202d1",
                            "lessThan": "e6cd1bba7d113c15c00ac63671213a096fe4d686",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "4cf476ced45d7f12df30a68e833b263e7a2202d1",
                            "lessThan": "ffc448eb54f5ba80d4212c1e870cdb92b0f709fa",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "4cf476ced45d7f12df30a68e833b263e7a2202d1",
                            "lessThan": "8e66c5969acd859ba72fb0a7fa895623fc1b3769",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "4cf476ced45d7f12df30a68e833b263e7a2202d1",
                            "lessThan": "e2f5529b0016db7d34f411408607f5cf395a542e",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "4cf476ced45d7f12df30a68e833b263e7a2202d1",
                            "lessThan": "30992fe39e65589ed8e000425e088fa74994b811",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "4cf476ced45d7f12df30a68e833b263e7a2202d1",
                            "lessThan": "ecc7253683a3c55caa868ce0ee530fcb0044bd3c",
                            "status": "affected",
                            "versionType": "git"
                        }
                    ]
                },
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "affected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "net/atm/pppoatm.c"
                    ],
                    "versions": [
                        {
                            "version": "5.11",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "5.11",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "5.15.222",
                            "lessThanOrEqual": "5.15.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.1.189",
                            "lessThanOrEqual": "6.1.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.6.158",
                            "lessThanOrEqual": "6.6.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.12.112",
                            "lessThanOrEqual": "6.12.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.18.54",
                            "lessThanOrEqual": "6.18.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.2.8",
                            "lessThanOrEqual": "7.2.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.3",
                            "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": "5.11",
                                    "versionEndExcluding": "5.15.222"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "5.11",
                                    "versionEndExcluding": "6.1.189"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "5.11",
                                    "versionEndExcluding": "6.6.158"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "5.11",
                                    "versionEndExcluding": "6.12.112"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "5.11",
                                    "versionEndExcluding": "6.18.54"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "5.11",
                                    "versionEndExcluding": "7.2.8"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "5.11",
                                    "versionEndExcluding": "7.3"
                                }
                            ]
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/208ccc4d08b1897451e9ba01c016bf93ff107966"
                },
                {
                    "url": "https://git.kernel.org/stable/c/e6cd1bba7d113c15c00ac63671213a096fe4d686"
                },
                {
                    "url": "https://git.kernel.org/stable/c/ffc448eb54f5ba80d4212c1e870cdb92b0f709fa"
                },
                {
                    "url": "https://git.kernel.org/stable/c/8e66c5969acd859ba72fb0a7fa895623fc1b3769"
                },
                {
                    "url": "https://git.kernel.org/stable/c/e2f5529b0016db7d34f411408607f5cf395a542e"
                },
                {
                    "url": "https://git.kernel.org/stable/c/30992fe39e65589ed8e000425e088fa74994b811"
                },
                {
                    "url": "https://git.kernel.org/stable/c/ecc7253683a3c55caa868ce0ee530fcb0044bd3c"
                }
            ],
            "title": "pppoatm: ensure a writable skb header and linear data",
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                "engine": "bippy-1.2.0"
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    }
}