Out-of-bounds write in Linux kernel - CVE-2026-31432
Published: April 24, 2026
Vulnerability identifier: #VU127715
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-31432
CWE-ID: CWE-787
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Linux Foundation
Affected software:
Linux kernel
Linux kernel
Detailed vulnerability description
The vulnerability allows a remote user to cause a denial of service.
The vulnerability exists due to an out-of-bounds write in smb2_get_info_sec() and build_sec_desc() when processing compound requests that include QUERY_INFO for security descriptors. A remote user can send a specially crafted compound request to cause a denial of service.
The issue is triggered when an earlier command in the same compound request consumes most of the response buffer, such as a READ request preceding QUERY_INFO(Security).
How to mitigate CVE-2026-31432
Install security update from vendor's repository.