Improper Enforcement of Behavioral Workflow in Linux kernel - CVE-2026-98901

Vulnerability identifier: #VU157602

CSH Severity: Low

CVSS v4: 5.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-98901

CWE-ID: CWE-841

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote user to compromise file cache consistency, potentially causing stale reads or file data corruption.

The vulnerability exists due to improper enforcement of lease state transitions in the Linux kernel ksmbd server when processing writes, truncates, and SMB2 lease break acknowledgments. A remote user can trigger incorrectly handled lease breaks and acknowledgments to leave caching states inconsistent with file operations, potentially causing stale reads or file data corruption.

Linux kernel
Ubuntu
linux (Ubuntu package)
linux-aws (Ubuntu package)
linux-gcp (Ubuntu package)
linux-oracle (Ubuntu package)
linux-ibm (Ubuntu package)
linux-hwe-7.0 (Ubuntu package)
linux-oem-7.0 (Ubuntu package)

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux (Ubuntu package) - update to 7.0.0-42.42
linux-aws (Ubuntu package) - update to 7.0.0-1016.17
linux-gcp (Ubuntu package) - update to 7.0.0-1016.18
linux-oracle (Ubuntu package) - update to 7.0.0-1015.16
linux-ibm (Ubuntu package) - update to 7.0.0-1017.17
linux-hwe-7.0 (Ubuntu package) - update to 7.0.0-42.42~24.04.1
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1017.17

• https://git.kernel.org/stable/c/17699905a381621c1cee5b6528feb05acedc86a4
• https://git.kernel.org/stable/c/3251ea36df5eef58aa207fbee48849d89b922ea6
• https://git.kernel.org/stable/c/5015191096db311759fef98769270336cd8b1324
• https://git.kernel.org/stable/c/fba4653a0b4dc2f6d42600abe21fb326292f70ff

• Improper Enforcement of Behavioral Workflow in Linux kernel smb server
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux, linux-aws, linux-gcp and more