Use of Uninitialized Variable in Linux kernel - CVE-2026-64220
Published: July 27, 2026
Vulnerability identifier: #VU139788
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-64220
CWE-ID: CWE-457
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vendor: Linux Foundation
Affected software:
Linux kernel
Linux kernel
Detailed vulnerability description
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to use of uninitialized memory in fwnode_init() when initializing a firmware node allocated on the stack or with a non-zeroing heap allocation. A local user can trigger code paths that dereference the uninitialized secondary pointer to cause a denial of service.
The issue can occur when a temporary software node is used and its lifetime is controlled by the caller.
How to mitigate CVE-2026-64220
Install security update from vendor's repository.
Sources
- https://git.kernel.org/stable/c/215c90ee656114f5e8c32408228d97082f8e0eef
- https://git.kernel.org/stable/c/34bf74b1fd2e4a44e27821a329204caf09df2976
- https://git.kernel.org/stable/c/371f53925a6714d0aa35f1aefdffc3e8cd62f480
- https://git.kernel.org/stable/c/3f1024deeab3b5443c29b3de4fe475e87309b8fa
- https://git.kernel.org/stable/c/508fd8ab158abd04b7f7d0f707cd6d6c405df4ea
- https://git.kernel.org/stable/c/f0e211d6539fae800217c10797993b7592d6ab01
- https://git.kernel.org/stable/c/f59e686c778cb41b8f7aa8fab2afd6a01afb3d47