{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-31536",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2026-03-09T15:48:24.113Z",
        "datePublished": "2026-04-24T14:30:24.224Z",
        "dateUpdated": "2026-08-05T12:23:21.869Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-08-05T12:23:21.869Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: server: let send_done handle a completion without IB_SEND_SIGNALED\n\nWith smbdirect_send_batch processing we likely have requests without\nIB_SEND_SIGNALED, which will be destroyed in the final request\nthat has IB_SEND_SIGNALED set.\n\nIf the connection is broken all requests are signaled\neven without explicit IB_SEND_SIGNALED."
                }
            ],
            "metrics": [
                {
                    "cvssV3_1": {
                        "version": "3.1",
                        "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
                        "baseScore": 9.8,
                        "baseSeverity": "CRITICAL"
                    },
                    "scenarios": [
                        {
                            "lang": "en",
                            "value": "AV:N - The vulnerable code is in ksmbd SMB Direct, which accepts remote RDMA/SMB Direct connections on network ports 445 and 5445 and processes peer-controlled SMB Direct traffic.\nAC:L - An attacker can negotiate a small SMB Direct max receive size to force batched multi-WR sends, then break the connection to make unsignaled sends complete with error. The disconnect/error condition is attacker-controlled rather than an external race.\nPR:N - The path is reachable before SMB authentication: SMB Direct negotiation completes first, and SMB2 NEGOTIATE/SESSION_SETUP do not require a valid session. A pre-auth remote client can trigger outbound responses through the vulnerable RDMA send batching path.\nUI:N - No victim user action is required once ksmbd with SMB Direct is listening; the attacker only needs to connect and send protocol messages.\nS:U - The impact is within the kernel/ksmbd host security authority and does not cross a hypervisor, IOMMU, or separate sandbox boundary.\nC:H - The bug is a use-after-free/double-free style memory corruption in RDMA send objects, and kernel UAFs can be shaped into disclosure primitives through heap reuse.\nI:H - The freed `smbdirect_send_io` objects contain list pointers, CQ callbacks, and work request state; corrupting or reusing them can plausibly support arbitrary write or control-flow hijack.\nA:H - Even without full exploitation, the UAF/list corruption is expected to cause kernel warnings, crashes, or hangs during RDMA QP drain and completion handling."
                        }
                    ]
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "fs/smb/server/transport_rdma.c"
                    ],
                    "versions": [
                        {
                            "version": "0626e6641f6b467447c81dd7678a69c66f7746cf",
                            "lessThan": "24082642654f3e5149913946e89c00a297a8868f",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "0626e6641f6b467447c81dd7678a69c66f7746cf",
                            "lessThan": "e38b415c024bc3b6321bf8650dbf3f4aab8e74b3",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "0626e6641f6b467447c81dd7678a69c66f7746cf",
                            "lessThan": "9da82dc73cb03e85d716a2609364572367a5ff47",
                            "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/smb/server/transport_rdma.c"
                    ],
                    "versions": [
                        {
                            "version": "5.15",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "5.15",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.18.11",
                            "lessThanOrEqual": "6.18.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.19.1",
                            "lessThanOrEqual": "6.19.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.0",
                            "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": "5.15",
                                    "versionEndExcluding": "6.18.11"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "5.15",
                                    "versionEndExcluding": "6.19.1"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "5.15",
                                    "versionEndExcluding": "7.0"
                                }
                            ]
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/24082642654f3e5149913946e89c00a297a8868f"
                },
                {
                    "url": "https://git.kernel.org/stable/c/e38b415c024bc3b6321bf8650dbf3f4aab8e74b3"
                },
                {
                    "url": "https://git.kernel.org/stable/c/9da82dc73cb03e85d716a2609364572367a5ff47"
                }
            ],
            "title": "smb: server: let send_done handle a completion without IB_SEND_SIGNALED",
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}