Race condition in Linux kernel - CVE-2026-64024
Published: July 20, 2026
Vulnerability identifier: #VU138620
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-64024
CWE-ID: CWE-362
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Linux Foundation
Affected software:
Linux kernel
Linux kernel
Detailed vulnerability description
The vulnerability allows a remote attacker to predict TCP initial sequence numbers.
The vulnerability exists due to improper state management in the Linux kernel TCP input path when processing TCP packets that transition from TIME_WAIT handling and are later dropped before request processing. A remote attacker can send packets that trigger these drop paths and then send a subsequent SYN on the same CPU to predict TCP initial sequence numbers.
The issue occurs because a non-zero TIME_WAIT-derived ISN can remain stored after several packet-drop conditions, including policy, filter, checksum, and header validation failures.
How to mitigate CVE-2026-64024
Install security update from vendor's repository.