Out-of-bounds read in Linux kernel - CVE-2026-31709
Published: May 2, 2026
Vulnerability identifier: #VU128994
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-31709
CWE-ID: CWE-125
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 attacker to cause a denial of service.
The vulnerability exists due to an out-of-bounds read in cifsacl DACL rewrite helpers when processing a server-supplied truncated DACL. A remote attacker can send a malformed ACL response to cause a denial of service.
The issue occurs because the incoming DACL body and each ACE were not structurally validated before chmod/chown security descriptor rebuild paths walked the ACE list.
How to mitigate CVE-2026-31709
Install security update from vendor's repository.