Use of Uninitialized Variable in Linux kernel - CVE-2026-64436

Vulnerability identifier: #VU139499

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-2026-64436

CWE-ID: CWE-457

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 use of uninitialized memory in pfkey_msg2xfrm_state() when processing a PF_KEY IPComp state and migrating it. A local user can add a crafted IPComp security association via PF_KEY and trigger migration to cause a denial of service.

The issue affects the PF_KEY path for IPComp states; the XFRM netlink path is not affected.

Linux kernel
openEuler
Ubuntu
bpftool
python3-perf-debuginfo
python3-perf
perf-debuginfo
perf
kernel-tools-devel
kernel-tools-debuginfo
kernel-tools
kernel-source
kernel-headers
kernel-devel
kernel-debugsource
kernel-debuginfo
bpftool-debuginfo
kernel
linux (Ubuntu package)
linux-gcp-7.0 (Ubuntu package)
linux-oem-7.0 (Ubuntu package)

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
bpftool - update to 5.10.0-330.0.0.231
python3-perf-debuginfo - update to 5.10.0-330.0.0.231
python3-perf - update to 5.10.0-330.0.0.231
perf-debuginfo - update to 5.10.0-330.0.0.231
perf - update to 5.10.0-330.0.0.231
kernel-tools-devel - update to 5.10.0-330.0.0.231
kernel-tools-debuginfo - update to 5.10.0-330.0.0.231
kernel-tools - update to 5.10.0-330.0.0.231
kernel-source - update to 5.10.0-330.0.0.231
kernel-headers - update to 5.10.0-330.0.0.231
kernel-devel - update to 5.10.0-330.0.0.231
kernel-debugsource - update to 5.10.0-330.0.0.231
kernel-debuginfo - update to 5.10.0-330.0.0.231
bpftool-debuginfo - update to 5.10.0-330.0.0.231
kernel - update to 5.10.0-330.0.0.231
linux (Ubuntu package) - addressed in versions 7.0.0-31.31, 7.0.0-31.31.1, 7.0.0-31.31~24.04.1, 7.0.0-1006.7, 7.0.0-1011.11~24.04.1, 7.0.0-1012.12, 7.0.0-1012.12~24.04.1
linux-gcp-7.0 (Ubuntu package) - update to 7.0.0-1011.11~24.04.1
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1013.13

• https://git.kernel.org/stable/c/01b9115b55018123ef2449ac4951f89147a8428e
• https://git.kernel.org/stable/c/273c06b81d2e902b21acc801ae18c8276c8a9b69
• https://git.kernel.org/stable/c/3f63d1752d90c0e28be931a48ab5d89bc97d637d
• https://git.kernel.org/stable/c/58e82fc3dedb57b1432292504415b224fd2d6acb
• https://git.kernel.org/stable/c/6de2a650917bedaaefd65b17cede83c5e2c1dedd
• https://git.kernel.org/stable/c/cea34abc94b0a81e3a8b5cfb41cf45af37c2c67e
• https://git.kernel.org/stable/c/d129c3177d7b1138fd5066fcc63a698b3ba415b0
• https://git.kernel.org/stable/c/e8417353cbd078d10531ba3928e609c84ab09e6b

• Use of Uninitialized Variable in Linux kernel key
• openEuler 22.03 LTS SP4 update for kernel
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux
• Ubuntu update for linux-gcp-7.0