Out-of-bounds read in Linux kernel - CVE-2026-89571

Vulnerability details

The vulnerability allows a local user to disclose kernel memory contents and cause a denial of service.

The vulnerability exists due to an out-of-bounds read in the cxlctl_fw_rpc() CXL fwctl command handler when processing a command whose operation size exceeds its input buffer. A local user can submit a crafted fwctl command with a large operation size to disclose kernel memory contents and cause a denial of service.

Affected software

How to mitigate CVE-2026-89571

External References

• https://git.kernel.org/stable/c/14d52c15d5d99477b20a2d61fe36f347080da6cd
• https://git.kernel.org/stable/c/d8957545fe96f7905791c937758ebfc1ae1e5b17
• https://git.kernel.org/stable/c/f687394af983df5660b6afae7e0d06969f3af206

Related Security Bulletins

• Out-of-bounds read in Linux kernel cxl core driver