Race condition in Linux kernel - CVE-2026-63978
Published: July 20, 2026
Vulnerability identifier: #VU138680
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-63978
CWE-ID: CWE-362
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 a race condition in net/handshake request draining during net namespace exit when canceling pending handshake requests concurrently with namespace teardown. A local user can trigger concurrent handshake request cancellation and net namespace destruction to cause a denial of service.
The issue affects pending handshake requests that have not yet been accepted and can result in list corruption or a request being freed while still linked on the drain loop's local list.
How to mitigate CVE-2026-63978
Install security update from vendor's repository.