Out-of-bounds read in Linux kernel - CVE-2026-72400

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Main Vulnerability Database Vulnerabilities #VU143042

Out-of-bounds read in Linux kernel - CVE-2026-72400

Published: August 15, 2026


Vulnerability identifier: #VU143042
CSH Severity: Low
CVSS v4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-72400
CWE-ID: CWE-125
Exploitation vector: Local access
Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a local user to disclose sensitive information.

The vulnerability exists due to an out-of-bounds read in seg6_validate_srh() when processing a BPF program-supplied Segment Routing Header length in the SEG6 encapsulation path. A local user can supply a crafted short SEG6 encapsulation header to disclose sensitive information.

Exploitation is reachable through the BPF SEG6 encap path, including the SEG6 local BPF END_B6 and END_B6_ENCAP actions.


Affected software

Linux kernel
Ubuntu
openEuler
kernel-tools
kernel
bpftool
bpftool-debuginfo
kernel-debuginfo
kernel-debugsource
kernel-devel
kernel-headers
kernel-source
kernel-tools-debuginfo
kernel-tools-devel
perf
perf-debuginfo
python3-perf
python3-perf-debuginfo
kernel-extra-modules
linux (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-oracle-5.15 (Ubuntu package)
linux-gcp-5.15 (Ubuntu package)
linux-gcp (Ubuntu package)
linux-azure-fde (Ubuntu package)
linux-nvidia-tegra (Ubuntu package)
linux-gcp-7.0 (Ubuntu package)
linux-oem-7.0 (Ubuntu package)
linux-azure-7.0 (Ubuntu package)
linux-azure (Ubuntu package)

How to mitigate CVE-2026-72400

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
kernel-tools - addressed in versions 6.6.0-145.1.24.161, 6.6.0-145.3.29.160
kernel - addressed in versions 6.6.0-145.1.24.161, 6.6.0-145.3.29.160
bpftool - addressed in versions 6.6.0-145.1.24.161, 6.6.0-145.3.29.160
bpftool-debuginfo - addressed in versions 6.6.0-145.1.24.161, 6.6.0-145.3.29.160
kernel-debuginfo - addressed in versions 6.6.0-145.1.24.161, 6.6.0-145.3.29.160
kernel-debugsource - addressed in versions 6.6.0-145.1.24.161, 6.6.0-145.3.29.160
kernel-devel - addressed in versions 6.6.0-145.1.24.161, 6.6.0-145.3.29.160
kernel-headers - addressed in versions 6.6.0-145.1.24.161, 6.6.0-145.3.29.160
kernel-source - addressed in versions 6.6.0-145.1.24.161, 6.6.0-145.3.29.160
kernel-tools-debuginfo - addressed in versions 6.6.0-145.1.24.161, 6.6.0-145.3.29.160
kernel-tools-devel - addressed in versions 6.6.0-145.1.24.161, 6.6.0-145.3.29.160
perf - addressed in versions 6.6.0-145.1.24.161, 6.6.0-145.3.29.160
perf-debuginfo - addressed in versions 6.6.0-145.1.24.161, 6.6.0-145.3.29.160
python3-perf - addressed in versions 6.6.0-145.1.24.161, 6.6.0-145.3.29.160
python3-perf-debuginfo - addressed in versions 6.6.0-145.1.24.161, 6.6.0-145.3.29.160
kernel-extra-modules - update to 6.6.0-145.3.29.160
linux (Ubuntu package) - addressed in versions 5.15.0-195.205~20.04.1, 5.15.0-195.205, 5.15.0-198.208~20.04.1, 5.15.0-198.208+fips1, 5.15.0-1080.84, 5.15.0-1100.108, 5.15.0-1109.111, 5.15.0-1109.114, 5.15.0-1111.115~20.04.1, 5.15.0-1111.115, 5.15.0-1112.118~20.04.1, 5.15.0-1112.118, 5.15.0-1113.119, 5.15.0-1114.120, 5.15.0-1116.125~20.04.1, 5.15.0-1117.124~20.04.1, 5.15.0-1117.124, 5.15.0-1117.124+fips1, 5.15.0-1122.131~20.04.1, 5.15.0-1123.132~20.04.1, 5.15.0-1123.132, 5.15.0-1123.132+fips1, 5.15.0.195.160, 5.15.0.195.205~20.04.1, 5.15.0.198.114, 5.15.0.198.171, 5.15.0.198.208~20.04.1, 5.15.0.1080.83~20.04.1, 5.15.0.1100.99, 5.15.0.1109.105, 5.15.0.1109.113, 5.15.0.1111.108, 5.15.0.1111.115~20.04.1, 5.15.0.1112.111, 5.15.0.1112.118~20.04.1, 5.15.0.1113.112, 5.15.0.1114.110, 5.15.0.1116.120, 5.15.0.1117.113, 5.15.0.1117.120, 5.15.0.1117.124~20.04.1, 5.15.0.1122.131~20.04.1, 5.15.0.1123.107, 5.15.0.1123.121, 5.15.0.1123.132~20.04.1, 7.0.0-38.38, 7.0.0-38.38.1, 7.0.0-1008.9, 7.0.0-1013.13~24.04.1, 7.0.0-1014.14, 7.0.0-1015.15
linux-nvidia (Ubuntu package) - addressed in versions 5.15.0-1112.113, 5.15.0.1112.112
linux-oracle-5.15 (Ubuntu package) - addressed in versions 5.15.0-1114.120~20.04.1, 5.15.0.1114.120~20.04.1
linux-gcp-5.15 (Ubuntu package) - addressed in versions 5.15.0-1118.128~20.04.1, 5.15.0.1118.128~20.04.1
linux-gcp (Ubuntu package) - addressed in versions 5.15.0-1118.128, 5.15.0-1118.128+fips1, 5.15.0.1118.107, 5.15.0.1118.115
linux-azure-fde (Ubuntu package) - addressed in versions 5.15.0-1122.131, 5.15.0.1122.131
linux-nvidia-tegra (Ubuntu package) - update to 6.8.0-1036.39+1
linux-gcp-7.0 (Ubuntu package) - addressed in versions 7.0.0-38.38~24.04.4, 7.0.0-1013.13~24.04.1, 7.0.0-1014.14~24.04.1
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1015.15
linux-azure-7.0 (Ubuntu package) - addressed in versions 7.0.0-1016.16~24.04.1, 7.0.0-1017.17~24.04.1
linux-azure (Ubuntu package) - addressed in versions 7.0.0-1016.16, 7.0.0-1017.17

External References

Related Security Bulletins