CVE-2026-90153
Received
Received - Intake
BaseFortify
Vulnerability report for CVE-2026-90153, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-09-17
Last updated on: 2026-09-18
Assigner: kernel.org
Description
Description
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: bound smb_check_perm_dacl() ACE walks by DACL size
smb_check_perm_dacl() validates that the DACL fits inside the NT
security descriptor, but then bounds its two ACE walks by the
remaining NTSD length (acl_size) rather than the DACL's declared
size (pdacl_size).
When pdacl->size is smaller than the trailing NTSD buffer, bytes
after the declared DACL boundary - still inside the stored security
descriptor - are parsed as ACEs during access checks. A crafted
DACL can place an access-granting ACE beyond pdacl->size, and the
current code accepts it during SMB2_CREATE access validation, while
parse_dacl() and smb_inherit_dacl() stop at pdacl_size.
Bound both ACE walks by pdacl_size to match the DACL boundary
semantics used elsewhere in the server.
Validation:
- semantic KUnit harness shows the post-boundary ACE is selected
before the fix and rejected (EACCES) after it
- linux master (7.2-rc6), x86_64
CVSS Scores
EPSS Scores
| Probability: | |
| Percentile: |
Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| Linux | Linux | 8f0541186e9ad1b62accc9519cc2b7a7240272a7 |
| Linux | Linux | 8f0541186e9ad1b62accc9519cc2b7a7240272a7 |
| Linux | Linux | 8f0541186e9ad1b62accc9519cc2b7a7240272a7 |
| Linux | Linux | 8f0541186e9ad1b62accc9519cc2b7a7240272a7 |
| Linux | Linux | 8f0541186e9ad1b62accc9519cc2b7a7240272a7 |
| Linux | Linux | cb69d4d6f709f87c94afa28ae64c501576692171 |
| Linux | Linux | 6e8f4abf584253cbaa596ea4ad13110cf61cd4c9 |
| Linux | Linux | 8e33102309bd6839b2e2e158f93a7b378cb4655d |
| Linux | Linux | 5.15.62 |
| Linux | Linux | 5.18.18 |
| Linux | Linux | 5.19.2 |
| Linux | Linux | 6.0 |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-UNKNOWN |
