High severity · published Jul 19, 2026
CVE-2026-64138
ksmbd: validate SID in parent security descriptor during ACL inheritance
8.8
CVSS
0.4%
EPSS
No
On KEV
Description
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: validate SID in parent security descriptor during ACL inheritance
Introduce smb_validate_ntsd_sid() helper to safely validate Owner SID
and Group SID inside the NT Security Descriptor (smb_ntsd) retrieved
from the parent directory.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 36% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
KE
Kernel · Linux
5.15 before 6.12.92; 6.13 before 6.18.34; 6.19 before 7.0.11; 7.1; 7.1; 7.1; +1 more · source: NVD
LI
Linux · Linux
e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 before 8efbea0253b7fa2d1960cab0fed36544ca0b41ab; e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 before f0e5c9c663badc9982e6941322eef1cb17de0f11; e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 before 18d8db24b0a5b7be4829238dd4022236df02d421; e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 before 1c9d0646a9959752f11ca1080dc1ff26bd1756cb; e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 before 69f030cf95488ae1186c72ac8c66fd279664ea7f; 5.15 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-64138
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-64138
Patch
https://git.kernel.org/stable/c/18d8db24b0a5b7be4829238dd4022236df02d421
Patch
https://git.kernel.org/stable/c/1c9d0646a9959752f11ca1080dc1ff26bd1756cb
Patch
https://git.kernel.org/stable/c/69f030cf95488ae1186c72ac8c66fd279664ea7f
git.kernel.org
https://git.kernel.org/stable/c/8efbea0253b7fa2d1960cab0fed36544ca0b41ab
Patch
https://git.kernel.org/stable/c/f0e5c9c663badc9982e6941322eef1cb17de0f11
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