Use-after-free in Linux kernel - CVE-2026-63917

Vulnerability identifier: #VU138737

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-2026-63917

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 the vti6 tunnel handling code in net/ipv6/ip6_vti.c when changing the configuration of a vti6 device after moving it across network namespaces. A local user can move a vti6 device between namespaces and then change its link parameters to cause a denial of service.

The issue is reachable from an unprivileged user namespace and may have cross-tenant impact on container hosts.

Linux kernel
openEuler
Ubuntu
kernel-debuginfo
python3-perf-debuginfo
python3-perf
perf-debuginfo
perf
kernel-tools-devel
kernel-tools-debuginfo
kernel-tools
kernel-source
kernel-headers
kernel-extra-modules
kernel-devel
kernel-debugsource
bpftool-debuginfo
bpftool
kernel
linux-ibm (Ubuntu package)
linux-aws (Ubuntu package)
linux-azure (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-nvidia-bos (Ubuntu package)

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
kernel-debuginfo - update to 6.6.0-145.3.29.160
python3-perf-debuginfo - update to 6.6.0-145.3.29.160
python3-perf - update to 6.6.0-145.3.29.160
perf-debuginfo - update to 6.6.0-145.3.29.160
perf - update to 6.6.0-145.3.29.160
kernel-tools-devel - update to 6.6.0-145.3.29.160
kernel-tools-debuginfo - update to 6.6.0-145.3.29.160
kernel-tools - update to 6.6.0-145.3.29.160
kernel-source - update to 6.6.0-145.3.29.160
kernel-headers - update to 6.6.0-145.3.29.160
kernel-extra-modules - update to 6.6.0-145.3.29.160
kernel-devel - update to 6.6.0-145.3.29.160
kernel-debugsource - update to 6.6.0-145.3.29.160
bpftool-debuginfo - update to 6.6.0-145.3.29.160
bpftool - update to 6.6.0-145.3.29.160
kernel - update to 6.6.0-145.3.29.160
linux-ibm (Ubuntu package) - addressed in versions 7.0.0-1008.8, 7.0.0-1010.10
linux-aws (Ubuntu package) - addressed in versions 7.0.0-1009.9, 7.0.0-1015.15
linux-azure (Ubuntu package) - addressed in versions 7.0.0-1009.9, 7.0.0-1010.10
linux-nvidia (Ubuntu package) - addressed in versions 7.0.0-1016.16, 7.0.0-1016.16~24.04.1
linux-nvidia-bos (Ubuntu package) - update to 7.0.0-2016.16

• https://git.kernel.org/stable/c/0cdce7618464f7fb06f461e8f4ad575cb1d570f4
• https://git.kernel.org/stable/c/11b326fb0a374f4654f9be22d0f0f7abd9f7d3fe
• https://git.kernel.org/stable/c/225b467e3b631f38be22e4b38062a1fed02fdd21
• https://git.kernel.org/stable/c/d9c5eecdb3c740e65038651db7c686b10d76d1bc
• https://git.kernel.org/stable/c/ee1778ba0f5cb53be771f97017d01eb356c797bf
• https://git.kernel.org/stable/c/f1e89a943ee574d0f2f16246eb3f2d7330fdeb03
• https://git.kernel.org/stable/c/f5c68875e25f331e497ddfbe81e2d8163a87f136
• https://git.kernel.org/stable/c/fc32be9ac2788524c6b24efd681cce7a6e731a92

• Use-after-free in Linux kernel ipv6
• Ubuntu update for linux-ibm
• Ubuntu update for linux-azure
• Ubuntu update for linux-aws
• Ubuntu update for linux-nvidia-bos
• Ubuntu update for linux-nvidia
• openEuler 24.03 LTS SP3 update for kernel