VULN/vuln-cve
1
0 Fork 0
Code Pull Requests Actions Activity
Files
c1444140e59c61ba154436ea0cd6284d8a97c3f0
vuln-cve/data/2026/64xxx/CVE-2026-64400.json
T

260 lines
13 KiB
JSON
Raw Blame History

{
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"cveMetadata": {
"cveId": "CVE-2026-64400",
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"state": "PUBLISHED",
"assignerShortName": "Linux",
"dateReserved": "2026-07-19T15:36:31.785Z",
"datePublished": "2026-07-25T08:50:43.655Z",
"dateUpdated": "2026-10-30T12:27:53.511Z"
},
"containers": {
"cna": {
"providerMetadata": {
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux",
"dateUpdated": "2026-10-30T12:27:53.511Z"
},
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: prevent path traversal bypass by restricting caseless retry\n\nksmbd_vfs_path_lookup() enforces LOOKUP_BENEATH to restrict path\nresolution within the share root. When a crafted path attempts to\nescape the share boundary using parent-directory components ('..'),\nvfs_path_parent_lookup() detects this and immediately fails,\nreturning -EXDEV.\n\nHowever, a bug exists in __ksmbd_vfs_kern_path() under caseless mode.\nThe function fails to intercept the -EXDEV error and erroneously\nfalls through to the caseless retry logic, which is intended only\nfor genuinely missing files. During this retry process, the path\nis reconstructed, leading to an unintended LOOKUP_BENEATH bypass\nthat allows write-capable users to create zero-length files or\ndirectories outside the exported share.\n\nFix this by ensuring that the execution only proceeds to the caseless\nlookup retry when the error is specifically -ENOENT. Any other errors,\nsuch as -EXDEV from a path traversal attempt, must be returned immediately."
}
],
"metrics": [
{
"cvssV3_1": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H",
"baseScore": 8.6,
"baseSeverity": "HIGH"
},
"scenarios": [
{
"lang": "en",
"value": "AV:N - The vulnerable lookup is reached remotely through SMB2 CREATE requests handled by ksmbd over TCP/445.\nAC:L - The attacker controls the crafted parent-directory path and can issue repeated or concurrent requests; any required lookup/create race is attacker-driven.\nPR:N - Although a valid SMB session and writable tree connection are required, ksmbd supports anonymous guest sessions on writable shares, requiring no prior privileges in a reasonable deployment.\nUI:N - Exploitation requires only attacker-generated SMB requests and no action by a victim.\nS:U - The bypass affects filesystems managed by the same host kernel and does not cross a virtualization or comparable security authority boundary.\nC:L - File contents are not exposed, but the out-of-share caseless directory walk and distinguishable errors can disclose limited pathname-existence metadata.\nI:L - The attacker can create chosen zero-length files or directories outside the export, but cannot supply file contents or overwrite arbitrary existing data through this flaw.\nA:H - Repeated creation in an escaped world-writable location can exhaust root-filesystem inodes, storage, or tmpfs memory and cause system-wide service unavailability."
}
]
}
],
"affected": [
{
"product": "Linux",
"vendor": "Linux",
"defaultStatus": "unaffected",
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"programFiles": [
"fs/smb/server/vfs.c"
],
"versions": [
{
"version": "6927ffe7479c72e7ebf885507227266a75f7c97d",
"lessThan": "21f050439db157f2afcc19885dec14549ca6ffc0",
"status": "affected",
"versionType": "git"
},
{
"version": "74d7970febf7e9005375aeda0df821d2edffc9f7",
"lessThan": "eec1dd2586c4016b7555a5d047db2b3756459fb2",
"status": "affected",
"versionType": "git"
},
{
"version": "74d7970febf7e9005375aeda0df821d2edffc9f7",
"lessThan": "a1c331d98313380c38f616c8b28b890ec8ef9c28",
"status": "affected",
"versionType": "git"
},
{
"version": "74d7970febf7e9005375aeda0df821d2edffc9f7",
"lessThan": "cfb5a56c218888f9d74165dff0c282cd0be97983",
"status": "affected",
"versionType": "git"
},
{
"version": "74d7970febf7e9005375aeda0df821d2edffc9f7",
"lessThan": "8c9a4f1327eb71efbf14842e7b8a6d965077eb67",
"status": "affected",
"versionType": "git"
},
{
"version": "74d7970febf7e9005375aeda0df821d2edffc9f7",
"lessThan": "54bab9ba5a9f156ffa9324fcbe5a356fd0242f95",
"status": "affected",
"versionType": "git"
},
{
"version": "019aae488dbc67c97a33db03652e20e2c9e3afa7",
"status": "affected",
"versionType": "git"
},
{
"version": "ef6cc1c465786b3e4e735d1ab8b616b3e94402df",
"status": "affected",
"versionType": "git"
},
{
"version": "6.1.71",
"lessThan": "6.1.191",
"status": "affected",
"versionType": "semver"
},
{
"version": "5.15.145",
"lessThan": "5.16",
"status": "affected",
"versionType": "semver"
},
{
"version": "6.3.10",
"lessThan": "6.4",
"status": "affected",
"versionType": "semver"
}
]
},
{
"product": "Linux",
"vendor": "Linux",
"defaultStatus": "affected",
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"programFiles": [
"fs/smb/server/vfs.c"
],
"versions": [
{
"version": "6.4",
"status": "affected"
},
{
"version": "0",
"lessThan": "6.4",
"status": "unaffected",
"versionType": "semver"
},
{
"version": "6.1.191",
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"versionType": "semver"
},
{
"version": "6.6.160",
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"versionType": "semver"
},
{
"version": "6.12.114",
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"versionType": "semver"
},
{
"version": "6.18.57",
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"versionType": "semver"
},
{
"version": "7.1.4",
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"versionType": "semver"
},
{
"version": "7.2",
"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": "6.1.71",
"versionEndExcluding": "6.1.191"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "6.4",
"versionEndExcluding": "6.6.160"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "6.4",
"versionEndExcluding": "6.12.114"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "6.4",
"versionEndExcluding": "6.18.57"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "6.4",
"versionEndExcluding": "7.1.4"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "6.4",
"versionEndExcluding": "7.2"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "5.15.145"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "6.3.10"
}
]
}
]
}
],
"references": [
{
"url": "https://git.kernel.org/stable/c/21f050439db157f2afcc19885dec14549ca6ffc0"
},
{
"url": "https://git.kernel.org/stable/c/eec1dd2586c4016b7555a5d047db2b3756459fb2"
},
{
"url": "https://git.kernel.org/stable/c/a1c331d98313380c38f616c8b28b890ec8ef9c28"
},
{
"url": "https://git.kernel.org/stable/c/cfb5a56c218888f9d74165dff0c282cd0be97983"
},
{
"url": "https://git.kernel.org/stable/c/8c9a4f1327eb71efbf14842e7b8a6d965077eb67"
},
{
"url": "https://git.kernel.org/stable/c/54bab9ba5a9f156ffa9324fcbe5a356fd0242f95"
}
],
"title": "ksmbd: prevent path traversal bypass by restricting caseless retry",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
}
}
View Git Blame Copy Permalink