Use-after-free in Linux kernel - CVE-2026-64002
Published: July 20, 2026
Vulnerability identifier: #VU138654
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-2026-64002
CWE-ID: CWE-416
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 use-after-free in ipv4_sysctl_exit_net() when unregistering the IPv4 sysctl table while sysctl handlers may still access sysctl_local_reserved_ports. A local user can trigger access to the freed sysctl entry to cause a denial of service.
The issue affects access to /proc/sys/net/ipv4/ip_local_reserved_ports during network namespace sysctl teardown.
How to mitigate CVE-2026-64002
Install security update from vendor's repository.
Sources
- https://git.kernel.org/stable/c/155f90be5ee8be5b110ebc0b7da33c54c83b0208
- https://git.kernel.org/stable/c/5b23a2ff379e70b6b9ff744a972b63e1f8f4d996
- https://git.kernel.org/stable/c/6512c57c4638ddec113bf42439361ba85a12048d
- https://git.kernel.org/stable/c/87a1e0fe7776da7ab411be332b4be58ac8840d10
- https://git.kernel.org/stable/c/8e59d4d0dcde2dfb07a7ef855c849a2a0560aa57
- https://git.kernel.org/stable/c/a0ffc6081a8b27082dd5eae5aa1e3f59bbecf06c
- https://git.kernel.org/stable/c/a7f4eefb6e1458431eef9fa20fb363320d185f76
- https://git.kernel.org/stable/c/ecf45080a4d3f4526cacb8b14060fe3b49a6913b