Improper control of a resource through its lifetime in Linux kernel - CVE-2026-64063

Vulnerability identifier: #VU138581

CSH Severity: Low

CVSS v4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-64063

CWE-ID: CWE-664

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to corrupt file data.

The vulnerability exists due to improper state management in netfs_perform_write() when handling streaming writes that overwrite partially written folios. A local user can perform crafted write operations to corrupt file data.

The issue can be triggered on netfs-backed filesystems such as cifs with the default cache option, and was observed when a streaming write page is later overwritten entirely or partially by a single write().

Linux kernel
Ubuntu
linux-ibm (Ubuntu package)
linux-azure (Ubuntu package)
linux-aws (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-nvidia-bos (Ubuntu package)

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux-ibm (Ubuntu package) - addressed in versions 7.0.0-1008.8, 7.0.0-1010.10
linux-azure (Ubuntu package) - addressed in versions 7.0.0-1009.9, 7.0.0-1010.10
linux-aws (Ubuntu package) - addressed in versions 7.0.0-1009.9, 7.0.0-1015.15
linux-nvidia (Ubuntu package) - addressed in versions 7.0.0-1016.16, 7.0.0-1016.16~24.04.1
linux-nvidia-bos (Ubuntu package) - update to 7.0.0-2016.16

• https://git.kernel.org/stable/c/20195925c768626dc901a4781a51e508702c88ad
• https://git.kernel.org/stable/c/7b4dcf1b9455a6e52ac7478b4057dbe10359576d
• https://git.kernel.org/stable/c/cdae00e8e215d95911d95f100599e187b6560de5
• https://git.kernel.org/stable/c/ef9b521212e4863814ef7dfe19889abaf55ca840

• Improper control of a resource through its lifetime in Linux kernel trace events
• Ubuntu update for linux-ibm
• Ubuntu update for linux-azure
• Ubuntu update for linux-aws
• Ubuntu update for linux-nvidia-bos
• Ubuntu update for linux-nvidia