GHSA-FXQH-HM36-RRQ9
Vulnerability from github – Published: 2026-08-10 12:31 – Updated: 2026-08-10 12:31In the Linux kernel, the following vulnerability has been resolved:
ksmbd: fix path resolution in ksmbd_vfs_kern_path_create
The SMB2 open lookup is rooted at the share with LOOKUP_BENEATH, but the create/mkdir/hardlink sink is not: ksmbd_vfs_kern_path_create() builds an absolute path with convert_to_unix_name() and resolves it from AT_FDCWD via start_creating_path(), so a ".." component is walked from the real filesystem root and escapes the export.
An authenticated client races a missing path component so the rooted open lookup returns -ENOENT (taking the create branch) while the same component is present (a directory) when the create walk runs; the create then resolves ".." out of the share.
Root the create walk at the share like the lookup and rename paths already are: resolve the parent with vfs_path_parent_lookup(..., LOOKUP_BENEATH, &share_conf->vfs_path) and create the final component with start_creating_noperm(). convert_to_unix_name() then has no callers and is removed.
{
"affected": [],
"aliases": [
"CVE-2026-68083"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-08-10T12:17:20Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fix path resolution in ksmbd_vfs_kern_path_create\n\nThe SMB2 open lookup is rooted at the share with LOOKUP_BENEATH, but the\ncreate/mkdir/hardlink sink is not: ksmbd_vfs_kern_path_create() builds an\nabsolute path with convert_to_unix_name() and resolves it from AT_FDCWD\nvia start_creating_path(), so a \"..\" component is walked from the real\nfilesystem root and escapes the export.\n\nAn authenticated client races a missing path component so the rooted open\nlookup returns -ENOENT (taking the create branch) while the same component\nis present (a directory) when the create walk runs; the create then\nresolves \"..\" out of the share.\n\nRoot the create walk at the share like the lookup and rename paths already\nare: resolve the parent with vfs_path_parent_lookup(..., LOOKUP_BENEATH,\n\u0026share_conf-\u003evfs_path) and create the final component with\nstart_creating_noperm(). convert_to_unix_name() then has no callers and is\nremoved.",
"id": "GHSA-fxqh-hm36-rrq9",
"modified": "2026-08-10T12:31:54Z",
"published": "2026-08-10T12:31:54Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-68083"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/1c8951963d8ed357f70f59e0ad4ddce2199d2016"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/489d1ded01425c0fb33418172c0e4e588467526b"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/98185b3025beeae92d1fe700d5db26b9ac4bf025"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/c7c884a1305aa4540eb7942a50bd356b34120e1f"
}
],
"schema_version": "1.4.0",
"severity": []
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
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- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.