#VU124964 Improper control of a resource through its lifetime in Linux kernel - CVE-2026-31409
Published: April 6, 2026
Vulnerability identifier: #VU124964
Vulnerability risk: Medium
CVSSv4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-31409
CWE-ID: CWE-664
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerable software:
Linux kernel
Linux kernel
Software vendor:
Linux Foundation
Linux Foundation
Description
The vulnerability allows a remote user to bypass session isolation.
The vulnerability exists due to improper state management in the ksmbd connection binding state when processing a multichannel SMB2_SESSION_SETUP request with SMB2_SESSION_REQ_FLAG_BINDING that fails. A remote user can send a failed binding request to bypass session isolation.
The issue occurs because subsequent ksmbd_session_lookup_all() calls fall back to the global sessions table after the connection remains in a binding state.
Remediation
Install security update from vendor's repository.
External links
- https://git.kernel.org/stable/c/282343cf8a4a5a3603b1cb0e17a7083e4a593b03
- https://git.kernel.org/stable/c/6260fc85ed1298a71d24a75d01f8b2e56d489a60
- https://git.kernel.org/stable/c/6ebef4a220a1ebe345de899ebb9ae394206fe921
- https://git.kernel.org/stable/c/89afe5e2dbea6e9d8e5f11324149d06fa3a4efca
- https://git.kernel.org/stable/c/9feb2d1bf86d9e5e66b8565f37f8d3a7d281a772
- https://git.kernel.org/stable/c/d073870dab8f6dadced81d13d273ff0b21cb7f4e