Integer overflow in Linux kernel - CVE-2026-31704
Published: May 2, 2026
Vulnerability identifier: #VU128989
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-31704
CWE-ID: CWE-190
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vendor: Linux Foundation
Affected software:
Linux kernel
Linux kernel
Detailed vulnerability description
The vulnerability allows a local user to cause memory corruption.
The vulnerability exists due to an integer overflow in set_posix_acl_entries_dacl() and set_ntacl_dacl() when processing files with many POSIX ACL entries. A local user can create a file with many POSIX ACL entries to cause memory corruption.
The accumulated DACL size can wrap past 65535, causing subsequent writes to overwrite earlier ACE entries and resulting in a truncated DACL size value.
How to mitigate CVE-2026-31704
Install security update from vendor's repository.
Sources
- https://git.kernel.org/stable/c/299f962c0b02d048fb45d248b4da493d03f3175d
- https://git.kernel.org/stable/c/5e7b8f3c539d69b2ed5f2408e2f75e68ce7eef43
- https://git.kernel.org/stable/c/8d5729350b236896f51379588d9a690b7fafb8db
- https://git.kernel.org/stable/c/e1955a94b6f17f4b058afa955a6f187eb3ed7615
- https://git.kernel.org/stable/c/ef7902be3f215b6bf7babe4dc9dd9a7d57dad7a7