Out-of-bounds write in Linux kernel - CVE-2026-31705
Published: May 2, 2026
Vulnerability identifier: #VU128990
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-2026-31705
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_ea() when processing crafted QUERY_INFO compound requests. A remote user can send a specially crafted request to cause a denial of service.
The issue occurs when EA alignment padding is applied after an EA value exactly fills the remaining response buffer, causing 1 to 3 bytes to be written past the boundary into adjacent kernel heap memory.
How to mitigate CVE-2026-31705
Install security update from vendor's repository.
Sources
- https://git.kernel.org/stable/c/30010c952077a1c89ecdd71fc4d574c75a8f5617
- https://git.kernel.org/stable/c/790304c02bf9bd7b8171feda4294d6e62d32ae8f
- https://git.kernel.org/stable/c/922d48fe8c19f388ffa2f709f33acaae4e408de2
- https://git.kernel.org/stable/c/98f3de6ef4efbd899348d333f0902dc4ff14380c
- https://git.kernel.org/stable/c/ffbce350c6fd1e99116ea57383b9031717e36d3b