Use of uninitialized resource in Linux kernel - CVE-2026-63870

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Main Vulnerability Database Vulnerabilities #VU138792

Use of uninitialized resource in Linux kernel - CVE-2026-63870

Published: July 20, 2026


Vulnerability identifier: #VU138792
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-2026-63870
CWE-ID: CWE-908
Exploitation vector: Local access
Exploit availability: No public exploit available

Vulnerability details

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

The vulnerability exists due to use of uninitialized memory in lowpan_xmit() in the ieee802154 6LoWPAN transmit path when processing a non-IPv6 packet queued for transmission on a 6LoWPAN interface. A local user can queue a non-IPv6 packet for transmission to cause a denial of service.

The issue occurs because address information in skb headroom may remain uninitialized and is later copied and used by the transmit path.


Affected software

Linux kernel
Ubuntu
openEuler
linux (Ubuntu package)
linux-kvm (Ubuntu package)
linux-aws (Ubuntu package)
linux-gcp (Ubuntu package)
linux-azure (Ubuntu package)
linux-oracle (Ubuntu package)
linux-lowlatency (Ubuntu package)
linux-gke (Ubuntu package)
linux-aws-5.15 (Ubuntu package)
linux-lowlatency-hwe-5.15 (Ubuntu package)
linux-hwe-5.15 (Ubuntu package)
linux-fips (Ubuntu package)
linux-azure-5.15 (Ubuntu package)
linux-nvidia-tegra-igx (Ubuntu package)
linux-intel-iotg (Ubuntu package)
linux-azure-fde-5.15 (Ubuntu package)
linux-realtime (Ubuntu package)
linux-ibm-5.15 (Ubuntu package)
linux-gkeop (Ubuntu package)
linux-nvidia-tegra (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-ibm (Ubuntu package)
linux-intel-iotg-5.15 (Ubuntu package)
linux-oracle-5.15 (Ubuntu package)
linux-gcp-5.15 (Ubuntu package)
linux-nvidia-tegra-5.15 (Ubuntu package)
linux-xilinx-zynqmp (Ubuntu package)
linux-intel-iot-realtime (Ubuntu package)
linux-gcp-fips (Ubuntu package)
linux-aws-fips (Ubuntu package)
linux-azure-fips (Ubuntu package)
linux-azure-fde (Ubuntu package)
linux-lowlatency-hwe-6.8 (Ubuntu package)
linux-azure-fde-6.8 (Ubuntu package)
linux-aws-6.8 (Ubuntu package)
linux-azure-6.8 (Ubuntu package)
linux-nvidia-lowlatency (Ubuntu package)
linux-nvidia-6.8 (Ubuntu package)
linux-ibm-6.8 (Ubuntu package)
linux-gcp-6.8 (Ubuntu package)
linux-realtime-6.8 (Ubuntu package)
linux-raspi (Ubuntu package)
linux-nvidia-bos (Ubuntu package)
linux-hwe-7.0 (Ubuntu package)
linux-oracle-7.0 (Ubuntu package)
linux-azure-7.0 (Ubuntu package)
linux-gcp-7.0 (Ubuntu package)
linux-oem-7.0 (Ubuntu package)
linux-aws-7.0 (Ubuntu package)
linux-nvidia-7.0 (Ubuntu package)
python3-perf-debuginfo
python3-perf
kernel
bpftool
bpftool-debuginfo
kernel-debuginfo
kernel-debugsource
kernel-devel
kernel-headers
kernel-source
kernel-tools
kernel-tools-debuginfo
kernel-tools-devel
perf
perf-debuginfo

How to mitigate CVE-2026-63870

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux (Ubuntu package) - addressed in versions 5.15.0-198.208, 6.8.0-146.146, 7.0.0-31.31
linux-kvm (Ubuntu package) - update to 5.15.0-1109.114
linux-aws (Ubuntu package) - addressed in versions 5.15.0-1117.124, 6.8.0-1066.69, 7.0.0-1012.12
linux-gcp (Ubuntu package) - addressed in versions 5.15.0-1118.128, 6.8.0-1070.78, 7.0.0-1011.11
linux-azure (Ubuntu package) - addressed in versions 5.15.0-1123.132, 6.8.0-1070.78, 7.0.0-1014.14
linux-oracle (Ubuntu package) - addressed in versions 5.15.0-1114.120, 6.8.0-1063.66, 7.0.0-1011.11
linux-lowlatency (Ubuntu package) - addressed in versions 5.15.0-195.205, 6.8.0-146.146.1
linux-gke (Ubuntu package) - addressed in versions 5.15.0-1113.119, 6.8.0-1065.73, 7.0.0-1006.7
linux-aws-5.15 (Ubuntu package) - update to 5.15.0-1117.124~20.04.1
linux-lowlatency-hwe-5.15 (Ubuntu package) - update to 5.15.0-195.205~20.04.1
linux-hwe-5.15 (Ubuntu package) - update to 5.15.0-198.208~20.04.1
linux-fips (Ubuntu package) - addressed in versions 5.15.0-198.208+fips1, 6.8.0-146.146+fips1
linux-azure-5.15 (Ubuntu package) - update to 5.15.0-1123.132~20.04.1
linux-nvidia-tegra-igx (Ubuntu package) - update to 5.15.0-1059.59
linux-intel-iotg (Ubuntu package) - update to 5.15.0-1112.118
linux-azure-fde-5.15 (Ubuntu package) - update to 5.15.0-1122.131~20.04.1
linux-realtime (Ubuntu package) - addressed in versions 5.15.0-1116.125, 6.8.1-1061.62, 7.0.0-31.31.1
linux-ibm-5.15 (Ubuntu package) - update to 5.15.0-1111.115~20.04.1
linux-gkeop (Ubuntu package) - addressed in versions 5.15.0-1100.108, 6.8.0-1051.55
linux-nvidia-tegra (Ubuntu package) - addressed in versions 5.15.0-1070.72, 6.8.0-1036.39
linux-nvidia (Ubuntu package) - addressed in versions 5.15.0-1112.113, 6.8.0-1064.67, 7.0.0-1018.18
linux-ibm (Ubuntu package) - addressed in versions 5.15.0-1111.115, 6.8.0-1066.67, 7.0.0-1013.13
linux-intel-iotg-5.15 (Ubuntu package) - update to 5.15.0-1112.118~20.04.1
linux-oracle-5.15 (Ubuntu package) - update to 5.15.0-1114.120~20.04.1
linux-gcp-5.15 (Ubuntu package) - update to 5.15.0-1118.128~20.04.1
linux-nvidia-tegra-5.15 (Ubuntu package) - update to 5.15.0-1070.72~20.04.1
linux-xilinx-zynqmp (Ubuntu package) - update to 5.15.0-1080.84
linux-intel-iot-realtime (Ubuntu package) - update to 5.15.0-1109.111
linux-gcp-fips (Ubuntu package) - addressed in versions 5.15.0-1118.128+fips1, 6.8.0-1070.78+fips1
linux-aws-fips (Ubuntu package) - addressed in versions 5.15.0-1117.124+fips1, 6.8.0-1066.69+fips1
linux-azure-fips (Ubuntu package) - addressed in versions 5.15.0-1123.132+fips1, 6.8.0-1069.77+fips1
linux-azure-fde (Ubuntu package) - update to 6.8.0-1068.75
linux-lowlatency-hwe-6.8 (Ubuntu package) - update to 6.8.0-146.146.1~22.04.1
linux-azure-fde-6.8 (Ubuntu package) - update to 6.8.0-1068.75~22.04.1
linux-aws-6.8 (Ubuntu package) - update to 6.8.0-1066.69~22.04.1
linux-azure-6.8 (Ubuntu package) - update to 6.8.0-1070.78~22.04.1
linux-nvidia-lowlatency (Ubuntu package) - update to 6.8.0-1064.67.1
linux-nvidia-6.8 (Ubuntu package) - update to 6.8.0-1064.67~22.04.1
linux-ibm-6.8 (Ubuntu package) - update to 6.8.0-1066.67~22.04.1
linux-gcp-6.8 (Ubuntu package) - update to 6.8.0-1070.78~22.04.1
linux-realtime-6.8 (Ubuntu package) - update to 6.8.1-1061.62~22.04.1
linux-raspi (Ubuntu package) - update to 7.0.0-1019.19
linux-nvidia-bos (Ubuntu package) - update to 7.0.0-2018.18
linux-hwe-7.0 (Ubuntu package) - update to 7.0.0-31.31~24.04.1
linux-oracle-7.0 (Ubuntu package) - update to 7.0.0-1011.11~24.04.1
linux-azure-7.0 (Ubuntu package) - update to 7.0.0-1014.14~24.04.1
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
linux-aws-7.0 (Ubuntu package) - update to 7.0.0-1012.12~24.04.1
linux-nvidia-7.0 (Ubuntu package) - update to 7.0.0-1018.18~24.04.1
python3-perf-debuginfo - update to 5.10.0-334.0.0.235
python3-perf - update to 5.10.0-334.0.0.235
kernel - update to 5.10.0-334.0.0.235
bpftool - update to 5.10.0-334.0.0.235
bpftool-debuginfo - update to 5.10.0-334.0.0.235
kernel-debuginfo - update to 5.10.0-334.0.0.235
kernel-debugsource - update to 5.10.0-334.0.0.235
kernel-devel - update to 5.10.0-334.0.0.235
kernel-headers - update to 5.10.0-334.0.0.235
kernel-source - update to 5.10.0-334.0.0.235
kernel-tools - update to 5.10.0-334.0.0.235
kernel-tools-debuginfo - update to 5.10.0-334.0.0.235
kernel-tools-devel - update to 5.10.0-334.0.0.235
perf - update to 5.10.0-334.0.0.235
perf-debuginfo - update to 5.10.0-334.0.0.235

External References

Related Security Bulletins