{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-80793",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2026-08-26T14:34:25.793Z",
        "datePublished": "2026-09-04T15:13:05.814Z",
        "dateUpdated": "2026-10-19T08:43:46.499Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-10-19T08:43:46.499Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nipv4: reject undersized MTUs in ip_do_fragment()\n\nip_do_fragment() subtracts the IPv4 header length from the effective\nMTU and passes the resulting payload MTU to ip_frag_next().\n\nIf the effective MTU is smaller than hlen + 8, ip_frag_next() rounds\nthe fragment payload length down to zero. The fragmentation state then\nnever makes forward progress: state->left, state->ptr and state->offset\nstay unchanged while ip_do_fragment() keeps allocating and transmitting\nheader-only fragments until the softlockup detector fires.\n\nThis is reproducible with a route installed using \"mtu lock 20\", but it\nis also reproducible without route MTU lock, for example by forwarding a\npacket to a device whose MTU is 20.\n\nFix it in ip_do_fragment() by rejecting mtu < hlen + 8 with -EMSGSIZE,\nmatching the existing IPv6 fragmentation check."
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "net/ipv4/ip_output.c"
                    ],
                    "versions": [
                        {
                            "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
                            "lessThan": "a716a64a4ba68cd46f2745fba2b1099fe8e0aa59",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
                            "lessThan": "515b6816ba0c12d8415c88e5f41e6ec029e35cfa",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
                            "lessThan": "74ce7389f8f562d39015f59a00ef7ad6acd37803",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
                            "lessThan": "b0ea911453ce7210e8200a07a94d2458bd1e6430",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
                            "lessThan": "36e0741833bd823866f8cb9f112f37cea1a70b60",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
                            "lessThan": "d9d1a676b033acabf8e5645f730486d1f8204a3f",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
                            "lessThan": "3556beb8ca86677af2aca5bfbed6f8e790fccc83",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
                            "lessThan": "c8a74adccaf028223054633b532593101dfcc581",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
                            "lessThan": "c0726f0caf8c6b3208552949e17d23634a2f3129",
                            "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/ipv4/ip_output.c"
                    ],
                    "versions": [
                        {
                            "version": "2.6.12",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "2.6.12",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "5.10.267",
                            "lessThanOrEqual": "5.10.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "5.15.218",
                            "lessThanOrEqual": "5.15.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.1.185",
                            "lessThanOrEqual": "6.1.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.6.154",
                            "lessThanOrEqual": "6.6.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.12.106",
                            "lessThanOrEqual": "6.12.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.18.47",
                            "lessThanOrEqual": "6.18.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.1.11",
                            "lessThanOrEqual": "7.1.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.2.1",
                            "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": "2.6.12",
                                    "versionEndExcluding": "5.10.267"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "2.6.12",
                                    "versionEndExcluding": "5.15.218"
                                },
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                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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                                {
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                                    "versionEndExcluding": "7.2.1"
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                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/a716a64a4ba68cd46f2745fba2b1099fe8e0aa59"
                },
                {
                    "url": "https://git.kernel.org/stable/c/515b6816ba0c12d8415c88e5f41e6ec029e35cfa"
                },
                {
                    "url": "https://git.kernel.org/stable/c/74ce7389f8f562d39015f59a00ef7ad6acd37803"
                },
                {
                    "url": "https://git.kernel.org/stable/c/b0ea911453ce7210e8200a07a94d2458bd1e6430"
                },
                {
                    "url": "https://git.kernel.org/stable/c/36e0741833bd823866f8cb9f112f37cea1a70b60"
                },
                {
                    "url": "https://git.kernel.org/stable/c/d9d1a676b033acabf8e5645f730486d1f8204a3f"
                },
                {
                    "url": "https://git.kernel.org/stable/c/3556beb8ca86677af2aca5bfbed6f8e790fccc83"
                },
                {
                    "url": "https://git.kernel.org/stable/c/c8a74adccaf028223054633b532593101dfcc581"
                },
                {
                    "url": "https://git.kernel.org/stable/c/c0726f0caf8c6b3208552949e17d23634a2f3129"
                }
            ],
            "title": "ipv4: reject undersized MTUs in ip_do_fragment()",
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}