Use-after-free in Linux kernel - CVE-2026-74743

Vulnerability identifier: #VU145980

CSH Severity: High

CVSS v4: 9.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-74743

CWE-ID: CWE-416

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to execute arbitrary code.

The vulnerability exists due to a use-after-free in the macvlan network device handling in drivers/net/macvlan.c when processing packets on a macvlan device backed by a lower device that requires additional headroom or tailroom. A remote attacker can send network traffic that triggers insufficient buffer space handling to execute arbitrary code.

The issue can be triggered when the lower device requires extra header or trailer space, such as with macsec, ipsec, wireguard, tunnels, or veth with rx headroom.

Linux kernel
openEuler
kernel
bpftool
bpftool-debuginfo
kernel-debuginfo
kernel-debugsource
kernel-devel
kernel-source
kernel-tools
kernel-tools-debuginfo
kernel-tools-devel
perf
perf-debuginfo
python2-perf
python2-perf-debuginfo
python3-perf
python3-perf-debuginfo

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
kernel - update to 4.19.90-2609.3.0.0391
bpftool - update to 4.19.90-2609.3.0.0391
bpftool-debuginfo - update to 4.19.90-2609.3.0.0391
kernel-debuginfo - update to 4.19.90-2609.3.0.0391
kernel-debugsource - update to 4.19.90-2609.3.0.0391
kernel-devel - update to 4.19.90-2609.3.0.0391
kernel-source - update to 4.19.90-2609.3.0.0391
kernel-tools - update to 4.19.90-2609.3.0.0391
kernel-tools-debuginfo - update to 4.19.90-2609.3.0.0391
kernel-tools-devel - update to 4.19.90-2609.3.0.0391
perf - update to 4.19.90-2609.3.0.0391
perf-debuginfo - update to 4.19.90-2609.3.0.0391
python2-perf - update to 4.19.90-2609.3.0.0391
python2-perf-debuginfo - update to 4.19.90-2609.3.0.0391
python3-perf - update to 4.19.90-2609.3.0.0391
python3-perf-debuginfo - update to 4.19.90-2609.3.0.0391

• https://git.kernel.org/stable/c/28afc87bd8da0b3348bbbd834c8a89e83712cf5e
• https://git.kernel.org/stable/c/8cd90e850e434577bf6774778657d26d6995e53f
• https://git.kernel.org/stable/c/8f6a05dbac05725e0786701eb04778c5bdbe4eaa
• https://git.kernel.org/stable/c/96fa90b74385b7f2b0d97251dd43d5ee6ca44668
• https://git.kernel.org/stable/c/bc9a00fb78e32bccc39d763bfd13a450705bac5d
• https://git.kernel.org/stable/c/cef51860becd9700217c81732ca1eb1ea6ed6fe1

• Use-after-free in Linux kernel net driver
• openEuler 20.03 LTS SP4 update for kernel