{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2025-68243",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2025-12-16T13:41:40.263Z",
        "datePublished": "2025-12-16T14:21:20.421Z",
        "dateUpdated": "2026-08-05T12:10:25.864Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-08-05T12:10:25.864Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nNFS: Check the TLS certificate fields in nfs_match_client()\n\nIf the TLS security policy is of type RPC_XPRTSEC_TLS_X509, then the\ncert_serial and privkey_serial fields need to match as well since they\ndefine the client's identity, as presented to the server."
                }
            ],
            "metrics": [
                {
                    "cvssV3_1": {
                        "version": "3.1",
                        "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H",
                        "baseScore": 7,
                        "baseSeverity": "HIGH"
                    },
                    "scenarios": [
                        {
                            "lang": "en",
                            "value": "AV:L - The vulnerable matching occurs during local NFS client setup or an internal referral/pNFS automount. A local attacker can consume an incorrectly credentialed mount, but arbitrary network packets alone cannot create the required client collision.\nAC:H - Exploitation requires a pre-existing mTLS client in the same network namespace with matching endpoint, protocol, NFS version, and minor version but a different, more privileged certificate, created in the favorable order. These deployment conditions are outside an unprivileged attacker’s control.\nPR:L - Directly creating the conflicting mount requires initial-user-namespace CAP_SYS_ADMIN because affected NFS filesystems lack FS_USERNS_MOUNT. However, an ordinary local user with access to an administrator-created misbound mount can exploit the stronger certificate identity.\nUI:N - Once the conflicting mounts or internal NFS clients exist, the attacker can access the misbound mount directly without another user taking an action.\nS:U - The flaw changes which NFS client identity the kernel presents but does not cross a VM, IOMMU, or sandbox security boundary.\nC:H - Reusing a more privileged client certificate can bypass server-side certificate authorization and expose entire sensitive NFS exports to unauthorized reads.\nI:H - If the inherited certificate authorizes write access, the attacker can modify or delete arbitrary data throughout protected NFS exports.\nA:H - The stronger identity can authorize destructive operations against service-critical exports, permitting deletion or corruption that makes the hosted data or dependent services unavailable."
                        }
                    ]
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "fs/nfs/client.c"
                    ],
                    "versions": [
                        {
                            "version": "90c9550a8d65fb9b1bf87baf97a04ed91bf61b33",
                            "lessThan": "b8fa37219074811c04d4ecb742c73e2b296da6a8",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "90c9550a8d65fb9b1bf87baf97a04ed91bf61b33",
                            "lessThan": "fb2cba0854a7f315c8100a807a6959b99d72479e",
                            "status": "affected",
                            "versionType": "git"
                        }
                    ]
                },
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "affected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "fs/nfs/client.c"
                    ],
                    "versions": [
                        {
                            "version": "6.17",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "6.17",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.17.9",
                            "lessThanOrEqual": "6.17.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.18",
                            "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": "6.17",
                                    "versionEndExcluding": "6.17.9"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.17",
                                    "versionEndExcluding": "6.18"
                                }
                            ]
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/b8fa37219074811c04d4ecb742c73e2b296da6a8"
                },
                {
                    "url": "https://git.kernel.org/stable/c/fb2cba0854a7f315c8100a807a6959b99d72479e"
                }
            ],
            "title": "NFS: Check the TLS certificate fields in nfs_match_client()",
            "x_generator": {
                "engine": "bippy-1.2.0"
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    }
}