{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-53250",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2026-06-09T07:44:35.394Z",
        "datePublished": "2026-06-25T08:39:42.630Z",
        "dateUpdated": "2026-08-05T12:34:33.657Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-08-05T12:34:33.657Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nxsk: cache csum_start/csum_offset to fix TOCTOU in xsk_skb_metadata()\n\nThe TX metadata area resides in the UMEM buffer which is memory-mapped\nand concurrently writable by userspace. In xsk_skb_metadata(),\ncsum_start and csum_offset are read from shared memory for bounds\nvalidation, then read again for skb assignment. A malicious userspace\napplication can race to overwrite these values between the two reads,\nbypassing the bounds check and causing out-of-bounds memory access\nduring checksum computation in the transmit path.\n\nFix this by reading csum_start and csum_offset into local variables\nonce, then using the local copies for both validation and assignment.\n\nNote that other metadata fields (flags, launch_time) and the cached\ncsum fields may be mutually inconsistent due to concurrent userspace\nwrites, but this is benign: the only security-critical invariant is\nthat each field's validated value is the same one used, which local\ncaching guarantees."
                }
            ],
            "metrics": [
                {
                    "cvssV3_1": {
                        "version": "3.1",
                        "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
                        "baseScore": 7.8,
                        "baseSeverity": "HIGH"
                    },
                    "scenarios": [
                        {
                            "lang": "en",
                            "value": "AV:L - The vulnerable path is reached by a local process using AF_XDP socket setup, UMEM registration, TX ring submission, and send/poll-driven transmit; it is not reachable directly from remote network packets.\nAC:L - The attacker controls the UMEM metadata and can trigger TX from the same process, so the TOCTOU race can be created with attacker-controlled concurrent writes.\nPR:L - AF_XDP socket creation requires CAP_NET_RAW in the relevant network namespace, which is attainable by a low-privileged local user in user/network namespace deployments.\nUI:N - No victim action is needed after the attacker has local execution; the attacker sets up the socket, UMEM, metadata, and transmit operation directly.\nS:U - The vulnerability corrupts or reads kernel networking memory within the same kernel security authority; this is standard local kernel attack surface, not a VM or hardware boundary crossing.\nC:H - Racing csum_start/csum_offset can bypass validation and drive out-of-bounds checksum reads in kernel transmit checksum handling, so potential kernel memory disclosure is high.\nI:H - The same unvalidated checksum offsets can cause checksum writes to an attacker-influenced out-of-bounds location relative to skb data, making kernel memory corruption plausible.\nA:H - The out-of-bounds memory access in the kernel transmit path can trigger warnings, faults, or kernel crashes and can be repeatedly exercised by the local attacker."
                        }
                    ]
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "net/xdp/xsk.c"
                    ],
                    "versions": [
                        {
                            "version": "48eb03dd26304c24f03bdbb9382e89c8564e71df",
                            "lessThan": "0dfe05b938435892875e07771170051346412df9",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "48eb03dd26304c24f03bdbb9382e89c8564e71df",
                            "lessThan": "bfdfd2706d5fb2cd496a1506e680daf979309c8b",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "48eb03dd26304c24f03bdbb9382e89c8564e71df",
                            "lessThan": "22ba97ea9cc1f63a0d0244fae38057ed452b6ac7",
                            "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/xdp/xsk.c"
                    ],
                    "versions": [
                        {
                            "version": "6.8",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "6.8",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.18.36",
                            "lessThanOrEqual": "6.18.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.0.13",
                            "lessThanOrEqual": "7.0.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.1",
                            "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": "6.8",
                                    "versionEndExcluding": "6.18.36"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.8",
                                    "versionEndExcluding": "7.0.13"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.8",
                                    "versionEndExcluding": "7.1"
                                }
                            ]
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/0dfe05b938435892875e07771170051346412df9"
                },
                {
                    "url": "https://git.kernel.org/stable/c/bfdfd2706d5fb2cd496a1506e680daf979309c8b"
                },
                {
                    "url": "https://git.kernel.org/stable/c/22ba97ea9cc1f63a0d0244fae38057ed452b6ac7"
                }
            ],
            "title": "xsk: cache csum_start/csum_offset to fix TOCTOU in xsk_skb_metadata()",
            "x_generator": {
                "engine": "bippy-1.2.0"
            }
        }
    }
}