Bug 2540469 (CVE-2026-93786) - CVE-2026-93786 kernel: ksmbd: preserve VFS inherited POSIX ACL mask
Summary: CVE-2026-93786 kernel: ksmbd: preserve VFS inherited POSIX ACL mask
Keywords:
Status: NEW
Alias: CVE-2026-93786
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-09-24 16:56 UTC by OSIDB Bzimport
Modified: 2026-09-28 10:12 UTC (History)
17 users (show)

Fixed In Version:
Clone Of:
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Description OSIDB Bzimport 2026-09-24 16:56:29 UTC 
In the Linux kernel, the following vulnerability has been resolved:

ksmbd: preserve VFS inherited POSIX ACL mask

The VFS initializes a child's POSIX ACL from the parent's default ACL and
the requested creation mode. Do not mutate the parent ACL or overwrite the
child's VFS-computed access and default ACLs afterwards.

This preserves restrictive ACL_MASK entries and prevents SMB object creation
from widening effective permissions.
Comment 1 Mauro Matteo Cascella 2026-09-28 10:08:19 UTC 
Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-93786.mbox
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