CVE-2026-99115 (GCVE-0-2026-99115)
Vulnerability from cvelistv5
Published
2026-10-28 10:34
Modified
2026-10-28 10:34
Severity ?
VLAI Severity ?
EPSS score ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: fill in FileSysIdentifier in FS_POSIX_INFORMATION
smb2_get_info_filesystem() reports 56 bytes for FS_POSIX_INFORMATION,
that is the whole of FILE_SYSTEM_POSIX_INFO, but never assigns
FileSysIdentifier. Those eight bytes go to the client as they are found
in the response buffer.
The buffer is zeroed on allocation, so a standalone request leaks
nothing. A compound request can leak: the offset of the next response
is advanced by the length pinned for the previous one, so a reply that
was written into the buffer and then dropped in favour of the short
error response of smb2_set_err_rsp() stays there, and the next reply is
laid over it with only the header cleared.
Report the file system id statfs() returned, which is what the field is
for. FileSysIdentifier is __le64 and f_fsid is a pair of ints, so
assemble the value first, val[0] as the low half, and convert it on the
way out.
References
Impacted products
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"fs/smb/server/smb2pdu.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "beba2ef6f66a71f20531ac70a1acb0b221e362e9",
"status": "affected",
"version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9",
"versionType": "git"
},
{
"lessThan": "ab057f271ef60ff8163818badc3de75c480eca07",
"status": "affected",
"version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9",
"versionType": "git"
},
{
"lessThan": "db2267b27c054a6c2151ff7fbb67927e784f31d6",
"status": "affected",
"version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"fs/smb/server/smb2pdu.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "5.15"
},
{
"lessThan": "5.15",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.59",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.2.*",
"status": "unaffected",
"version": "7.2.13",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.18.59",
"versionStartIncluding": "5.15",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.2.13",
"versionStartIncluding": "5.15",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.3",
"versionStartIncluding": "5.15",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fill in FileSysIdentifier in FS_POSIX_INFORMATION\n\nsmb2_get_info_filesystem() reports 56 bytes for FS_POSIX_INFORMATION,\nthat is the whole of FILE_SYSTEM_POSIX_INFO, but never assigns\nFileSysIdentifier. Those eight bytes go to the client as they are found\nin the response buffer.\n\nThe buffer is zeroed on allocation, so a standalone request leaks\nnothing. A compound request can leak: the offset of the next response\nis advanced by the length pinned for the previous one, so a reply that\nwas written into the buffer and then dropped in favour of the short\nerror response of smb2_set_err_rsp() stays there, and the next reply is\nlaid over it with only the header cleared.\n\nReport the file system id statfs() returned, which is what the field is\nfor. FileSysIdentifier is __le64 and f_fsid is a pair of ints, so\nassemble the value first, val[0] as the low half, and convert it on the\nway out."
}
],
"providerMetadata": {
"dateUpdated": "2026-10-28T10:34:32.347Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/beba2ef6f66a71f20531ac70a1acb0b221e362e9"
},
{
"url": "https://git.kernel.org/stable/c/ab057f271ef60ff8163818badc3de75c480eca07"
},
{
"url": "https://git.kernel.org/stable/c/db2267b27c054a6c2151ff7fbb67927e784f31d6"
}
],
"title": "ksmbd: fill in FileSysIdentifier in FS_POSIX_INFORMATION",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-99115",
"datePublished": "2026-10-28T10:34:32.347Z",
"dateReserved": "2026-09-25T10:25:14.392Z",
"dateUpdated": "2026-10-28T10:34:32.347Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
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