Improper Initialization in Linux kernel - CVE-2026-31710
Published: May 2, 2026
Vulnerability identifier: #VU128977
CSH Severity: Low
CVSS v4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-31710
CWE-ID: CWE-665
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to cause incorrect path handling.
The vulnerability exists due to improper state management in cifs_mount_get_tcon() for SMB1 UNIX mounts when updating mount flags during mount processing. A local user can trigger the use of incorrect directory separators in paths to cause incorrect path handling.
The issue occurs when SMB1 UNIX mounts are used and the CIFS_MOUNT_POSIX_PATHS bit is missing from mnt_cifs_flags.
Affected software
Linux kernel
Ubuntu
linux (Ubuntu package)
linux-azure (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-raspi (Ubuntu package)
Ubuntu
linux (Ubuntu package)
linux-azure (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-raspi (Ubuntu package)
How to mitigate CVE-2026-31710
Install security update from vendor's repository.
Linux kernel - update to 7.0 rc3
linux (Ubuntu package) - update to 7.0.0-27.27
linux-azure (Ubuntu package) - addressed in versions 7.0.0-1009.9, 7.0.0-1010.10
linux-nvidia (Ubuntu package) - update to 7.0.0-1013.13
linux-raspi (Ubuntu package) - update to 7.0.0-1014.14
linux (Ubuntu package) - update to 7.0.0-27.27
linux-azure (Ubuntu package) - addressed in versions 7.0.0-1009.9, 7.0.0-1010.10
linux-nvidia (Ubuntu package) - update to 7.0.0-1013.13
linux-raspi (Ubuntu package) - update to 7.0.0-1014.14