cve.bz

CVE-2026-90153

8.1 highEPSS 0.5%

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 3.1
8.1CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
EPSS
0.5% chance of exploitation in the next 30 days; higher than 40% of CVEs (scores of 2026-10-25)
Published
Modified
Record from
the NVD, synced

References

Check your stackJSON