{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-64074",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2026-07-19T07:54:57.031Z",
        "datePublished": "2026-07-19T15:39:49.076Z",
        "dateUpdated": "2026-08-05T12:38:55.440Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-08-05T12:38:55.440Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nfs/statmount: fix slab out-of-bounds write in statmount_mnt_idmap\n\nstatmount_mnt_idmap() writes one mapping with seq_printf() and then\nmanually advances seq->count to include the NUL separator.\n\nIf seq_printf() overflows, seq_set_overflow() sets seq->count to\nseq->size. The manual seq->count++ changes this to seq->size + 1.\nseq_has_overflowed() then no longer detects the overflow. The corrupted\ncount returns to statmount_string(), which later executes:\n\n    seq->buf[seq->count++] = '\\0';\n\nThis causes a 1-byte NULL out-of-bounds write on the dynamically\nallocated seq buffer.\n\nFix this by checking for overflow immediately after seq_printf()."
                }
            ],
            "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 bug is reachable only through the statmount(2) syscall when requesting mount UID/GID map strings; there is no network, adjacent, or physical entry path to this code.\nAC:L - An attacker fully controls statmount mask, buffer sizing, mount paths/options, and idmap extent values to reliably drive seq_printf() to overflow at the vulnerable count++ site without depending on uncontrollable timing or layout.\nPR:L - Exploitation requires creating or querying an idmapped mount via statmount, which an unprivileged local user can do in their own user/mount namespaces where CAP_SYS_ADMIN is granted by user namespaces.\nUI:N - Triggering the flaw requires only the attacker's own statmount syscall and crafted namespace/mount setup; no action by another user or victim is needed.\nS:U - Impact is kernel heap corruption and potential privilege escalation within the same kernel security domain, not a cross-boundary escape such as VM guest-to-host.\nC:H - The flaw is a slab out-of-bounds write that corrupts adjacent heap memory; per kernel CVSS guidance, exploitable memory corruption warrants High confidentiality impact even if direct read is not guaranteed.\nI:H - A one-byte out-of-bounds NULL write into adjacent kmalloc slab objects can corrupt kernel metadata and be leveraged for arbitrary memory modification or code execution.\nA:H - Heap corruption from the out-of-bounds write can cause kernel oops/panic or destabilize the system, and memory-corruption bugs are scored as High availability impact."
                        }
                    ]
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "fs/mnt_idmapping.c"
                    ],
                    "versions": [
                        {
                            "version": "37c4a9590e1efcae7749682239fc22a330d2d325",
                            "lessThan": "e37ea2c6f17f273813ea4e8e94c102591d598ce1",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "37c4a9590e1efcae7749682239fc22a330d2d325",
                            "lessThan": "93614949dc86f068e3c32c32cf1ee2a2323177a7",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "37c4a9590e1efcae7749682239fc22a330d2d325",
                            "lessThan": "a3bf0f28d4ba16e1f35f8c983bb04426b87e2a78",
                            "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/mnt_idmapping.c"
                    ],
                    "versions": [
                        {
                            "version": "6.15",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "6.15",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.18.34",
                            "lessThanOrEqual": "6.18.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.0.11",
                            "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": "6.15",
                                    "versionEndExcluding": "6.18.34"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.15",
                                    "versionEndExcluding": "7.0.11"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.15",
                                    "versionEndExcluding": "7.1"
                                }
                            ]
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/e37ea2c6f17f273813ea4e8e94c102591d598ce1"
                },
                {
                    "url": "https://git.kernel.org/stable/c/93614949dc86f068e3c32c32cf1ee2a2323177a7"
                },
                {
                    "url": "https://git.kernel.org/stable/c/a3bf0f28d4ba16e1f35f8c983bb04426b87e2a78"
                }
            ],
            "title": "fs/statmount: fix slab out-of-bounds write in statmount_mnt_idmap",
            "x_generator": {
                "engine": "bippy-1.2.0"
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}