ksmbd: validate ACE size against SID sub-authorities

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-68097
StatePUBLISHED
AssignerLinux
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-08-10 13:19:54 UTC
Updated2026-08-17 05:18:09 UTC
DescriptionIn the Linux kernel, the following vulnerability has been resolved: ksmbd: validate ACE size against SID sub-authorities set_ntacl_dacl() validates sid.num_subauth before copying an ACE, but does not verify that the declared ACE size contains all sub-authorities described by that field. An undersized ACE can therefore be copied and later make the POSIX ACL deduplication walk inspect data beyond the copied ACE boundary. The existing initial bound check is also too small. It only ensures that the ACE size field is accessible before set_ntacl_dacl() reads sid.num_subauth farther into the input buffer. Require enough input for the fixed SID header before accessing num_subauth, reject ACEs smaller than that header, and skip ACEs whose declared size cannot contain the complete SID. This makes the validation consistent with the other ACE walk paths.

Risk And Classification

Primary CVSS: v3.1 8.8 HIGH from 416baaa9-dc9f-4396-8d5f-8c081fb06d67

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS: 0.004140000 probability, percentile 0.345360000 (date 2026-08-17)

VersionSourceTypeScoreSeverityVector
3.1416baaa9-dc9f-4396-8d5f-8c081fb06d67Secondary8.8HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
3.1CNADECLARED8.8HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Linux Linux affected e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 b7cb5bf0855470799f12da825de91e48951b3876 git Not specified
CNA Linux Linux affected e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 62d80d7c2d9428085e7458ad4c06ca8c0984039b git Not specified
CNA Linux Linux affected e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 337022d9dfac441c3b35e4455a51aa981996e02e git Not specified
CNA Linux Linux affected e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 61fd3559199f7fa693dcbff35e59477e24af041a git Not specified
CNA Linux Linux affected e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 5152c6d49e3fd4e9f2e857c57527aead752f1f87 git Not specified
CNA Linux Linux affected 5.15 Not specified
CNA Linux Linux unaffected 5.15 semver Not specified
CNA Linux Linux unaffected 6.6.148 6.6.* semver Not specified
CNA Linux Linux unaffected 6.12.101 6.12.* semver Not specified
CNA Linux Linux unaffected 6.18.42 6.18.* semver Not specified
CNA Linux Linux unaffected 7.1.6 7.1.* semver Not specified
CNA Linux Linux unaffected 7.2 * original_commit_for_fix Not specified

References

ReferenceSourceLinkTags
git.kernel.org/stable/c/b7cb5bf0855470799f12da825de91e48951b3876 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/337022d9dfac441c3b35e4455a51aa981996e02e 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/62d80d7c2d9428085e7458ad4c06ca8c0984039b 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/61fd3559199f7fa693dcbff35e59477e24af041a 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/5152c6d49e3fd4e9f2e857c57527aead752f1f87 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
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