SB2026050921 - Use-after-free in Linux kernel smb server
Published: May 9, 2026
Security Bulletin ID
SB2026050921
CSH Severity
Low
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Local access
Highest impact
Code execution
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Use-after-free (CVE-ID: CVE-2026-43378)
CWE-ID: CWE-416 - Use After Free
CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
The vulnerability allows a local user to execute arbitrary code.
The vulnerability exists due to use-after-free in smb2_open() when handling SMB open requests. A local user can trigger a race condition involving a dangling opinfo pointer to execute arbitrary code.
Remediation
Install update from vendor's website.
References
- https://git.kernel.org/stable/c/190e5f808e8058640b408ccfed25440b441a718a
- https://git.kernel.org/stable/c/1e689a56173827669a35da7cb2a3c78ed5c53680
- https://git.kernel.org/stable/c/54b48ae83de8bb06e65079d96368efe359d4909c
- https://git.kernel.org/stable/c/8f5b1a7cb009a93c48e9e334a2f59a660f9afc07
- https://git.kernel.org/stable/c/b720c84087cb547f23ce03eab93568c1769e4556
- https://git.kernel.org/stable/c/e1b21e6066615e7d3d3a7aa2677e415e563fd7cc