ksmbd: fix maximum allowed access checks
Severity and exploitation
KEV coverage does not rule out exploitation.
Assessment vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:NSeverity
high8.1CVSS measures technical severity, not the likelihood of an attack.
Known exploitation
Not listed in the checked CISA KEV catalog
Absence from CISA KEV does not rule out attacks.
Public exploit
Not established by this record
Missing evidence does not mean no public exploit exists.
Remediation
Fix status not established
No structured fix or guidance is available here. Check the latest publisher advisory.
What this means
In the Linux kernel, the following vulnerability has been resolved:
Source excerpt · LinuxAttack conditions
Access to the system ACL requires a security privilege that ksmbd does not grant.
Excerpt from the original source description below.
Review supporting sources →Affected versions
Check the exact model, release, and any platform requirements against your installation.
Linux · Linux
Linux
6 ranges
Linux · Linux
Linux
Compare with this publisher’s ranges. This does not inspect your installation.
affected
e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 → before faf0b894eedc7b2ebb36c48d04d412240dd0ea71
git versions
e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 → before 7c293e83d86cfd38124f51b27882ad631818bf48
git versions
e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 → before 37459edb69c094553026ee48c2cc2acc657f9f43
git versions
e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 → before 28289d880e6d11ae7ac77b81af3312453febf939
git versions
e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 → before 35d5c59fe6b1d9fe43fb14eb384f69ee1a120f9c
git versions
e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 → before cc2f133e80eb2c4a04bfa77a2f207749fe2f516a
git versions
Other versions: unaffected
Linux · Linux
Linux
8 ranges
Linux · Linux
Linux
Compare with this publisher’s ranges. This does not inspect your installation.
affected
5.15
unaffected
0 → before 5.15
semver versions
6.1.191 → through 6.1.*
semver versions
6.6.160 → through 6.6.*
semver versions
6.12.114 → through 6.12.*
semver versions
6.18.57 → through 6.18.*
semver versions
7.2.6 → through 7.2.*
semver versions
7.3 → through *
original_commit_for_fix versions
Other versions: affected
What to do
Compare your installed product and version with the affected versions above. A matching product name alone does not confirm exposure.
No structured fix or remediation guidance is available here. Check the full source description and vendor’s latest advisory for a patch or workaround; do not assume another version is safe.
cve.new guidance unless attributed to a publisher. This page does not inspect your installation.
Public exploit evidence
No public exploit reference is identified in the imported evidence. This is not a claim that no exploit exists.
Original source description
Read the full publisher description
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: fix maximum allowed access checks
The DACL permission check looks for an ACE matching the current user and falls back to the Everyone ACE. It does not consider an Authenticated Users ACE, even though an authenticated session is a member of that well-known group.
As a result, opening a file whose access is granted through S-1-5-11 can incorrectly fail with STATUS_ACCESS_DENIED. Treat an Authenticated Users ACE as a fallback entry alongside Everyone.
The maximal access calculation also combines access masks from every ACE, regardless of whether its SID applies to the current user. This can grant rights belonging to an unrelated principal. Process only ACEs applying to the user, Everyone, or Authenticated Users, and accumulate allowed and denied masks in ACL order. Preserve explicitly requested access bits so they are validated against the resulting maximal mask.
When ACCESS_SYSTEM_SECURITY is denied, report STATUS_PRIVILEGE_NOT_HELD instead of the generic STATUS_ACCESS_DENIED. Access to the system ACL requires a security privilege that ksmbd does not grant.
For regular files, include FILE_EXECUTE in maximal access when the client requested GENERIC_EXECUTE and the DACL grants the complete file-read set. Keep a direct FILE_EXECUTE request subject to the explicit DACL bit. This matches the POSIX file ACL mapping without broadening specific execute requests.
Do not replace rights from an applicable NT ACE with a POSIX ACL entry. The POSIX ACL is only a fallback when no user, Everyone, or Authenticated Users ACE applies; otherwise it can incorrectly broaden the stored DACL.
This fixes smb2.maximum_allowed.maximum_allowed.
References
6 sourcesInside the record
Evidence available
Describes the evidence in this view, not whether the product is safe.
Original records
CVE-2026-93282View the latest unmodified CVE JSON from the official source. It may be newer than this imported page.
cve.new JSON →Environment requirements
These conditions apply together as specified by the publisher. A matching product name alone does not establish exposure.
Linux · platform conditions
Any condition may hold
Vulnerable product
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*From (inclusive): 5.15
Before: 6.1.191
Vulnerable product
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*From (inclusive): 5.15
Before: 6.6.160
Vulnerable product
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*From (inclusive): 5.15
Before: 6.12.114
Vulnerable product
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*From (inclusive): 5.15
Before: 6.18.57
Vulnerable product
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*From (inclusive): 5.15
Before: 7.2.6
Vulnerable product
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*From (inclusive): 5.15
Before: 7.3
Applicability preview
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]Contributing organizations · 1
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Timeline
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Last imported by cve.new
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What changed
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