Heap-based buffer overflow in Linux kernel - CVE-2026-64449

 

Heap-based buffer overflow in Linux kernel - CVE-2026-64449

Published: July 27, 2026


Vulnerability identifier: #VU139496
CSH Severity: Low
CVSS v4: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-64449
CWE-ID: CWE-122
Exploitation vector: Local access
Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a local user to cause a denial of service or execute arbitrary code.

The vulnerability exists due to a heap-based buffer overflow in the SLAVE-path helpers buffer_to_user() and buffer_from_user() in drivers/staging/vme_user/vme_user.c when processing read and write operations with an offset and count that exceed the fixed kern_buf size. A local user can issue crafted read or write operations to cause a denial of service or execute arbitrary code.

The issue occurs when the configured slave window exceeds the 128 KiB kern_buf allocation.


Affected software

Linux kernel
Ubuntu
linux (Ubuntu package)
linux-gcp-7.0 (Ubuntu package)
linux-oem-7.0 (Ubuntu package)

How to mitigate CVE-2026-64449

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux (Ubuntu package) - addressed in versions 7.0.0-31.31, 7.0.0-31.31.1, 7.0.0-31.31~24.04.1, 7.0.0-1006.7, 7.0.0-1011.11~24.04.1, 7.0.0-1012.12, 7.0.0-1012.12~24.04.1
linux-gcp-7.0 (Ubuntu package) - update to 7.0.0-1011.11~24.04.1
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1013.13

External References

Related Security Bulletins