Use-after-free in Linux kernel - CVE-2026-74289

Vulnerability identifier: #VU142903

CSH Severity: Low

CVSS v4: 6.8 [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]

CVE-ID: CVE-2026-74289

CWE-ID: CWE-416

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to a use-after-free in fib_leaf_notify() and fib_info reference handling when dumping IPv4 fib_info entries under RCU during fib notifier processing. A local user can trigger network namespace cleanup or device reload operations that invoke affected fib notifier paths to cause a denial of service.

The issue was reported through the netdevsim notifier path, and IPv6 is not affected by the same condition.

Linux kernel
openEuler
kernel
bpftool
bpftool-debuginfo
kernel-debuginfo
kernel-debugsource
kernel-devel
kernel-extra-modules
kernel-headers
kernel-source
kernel-tools
kernel-tools-debuginfo
kernel-tools-devel
perf
perf-debuginfo
python3-perf
python3-perf-debuginfo

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
kernel - update to 6.6.0-145.3.31.162
bpftool - update to 6.6.0-145.3.31.162
bpftool-debuginfo - update to 6.6.0-145.3.31.162
kernel-debuginfo - update to 6.6.0-145.3.31.162
kernel-debugsource - update to 6.6.0-145.3.31.162
kernel-devel - update to 6.6.0-145.3.31.162
kernel-extra-modules - update to 6.6.0-145.3.31.162
kernel-headers - update to 6.6.0-145.3.31.162
kernel-source - update to 6.6.0-145.3.31.162
kernel-tools - update to 6.6.0-145.3.31.162
kernel-tools-debuginfo - update to 6.6.0-145.3.31.162
kernel-tools-devel - update to 6.6.0-145.3.31.162
perf - update to 6.6.0-145.3.31.162
perf-debuginfo - update to 6.6.0-145.3.31.162
python3-perf - update to 6.6.0-145.3.31.162
python3-perf-debuginfo - update to 6.6.0-145.3.31.162

• https://git.kernel.org/stable/c/06b693d2eb6651a63ad85bad8673de3b7d4edd6d
• https://git.kernel.org/stable/c/676482da8d938ea72c26da0fc86af2d2ec238ab2

• Use-after-free in Linux kernel ipv4
• openEuler 24.03 LTS SP3 update for kernel