SB2026091960 - Incorrect authorization in Linux kernel smb server
Published: September 19, 2026
Security Bulletin ID
SB2026091960
CSH Severity
High
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Remote access
Highest impact
Data manipulation
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Incorrect authorization (CVE-ID: CVE-2026-90153)
CWE-ID: CWE-863 - Incorrect Authorization
CVSSv4: 9.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to gain unauthorized access.
The vulnerability exists due to improper authorization in smb_check_perm_dacl() in the ksmbd SMB server when processing a crafted DACL during SMB2_CREATE access validation. A remote attacker can submit a crafted DACL containing an access-granting ACE beyond its declared boundary to gain unauthorized access.
Remediation
Install update from vendor's website.
References
- https://git.kernel.org/stable/c/79decd88dd3f0d42e7fb0689b1a7853bfa302459
- https://git.kernel.org/stable/c/8e4f75e979c1d9a51b0a48ac33d0cfd5f039ec67
- https://git.kernel.org/stable/c/a2051ffe452afad52f580b85a3fd8851933b1e7c
- https://git.kernel.org/stable/c/a29f57a14c939586d84d7fd6a029bd1fd170098f
- https://git.kernel.org/stable/c/a4a307d149327dad5fb25187e1b03cebd1b04de6