Out-of-bounds read in Linux kernel - CVE-2026-52927

Vulnerability identifier: #VU135455

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-2026-52927

CWE-ID: CWE-125

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to disclose sensitive information.

The vulnerability exists due to an out-of-bounds read in compat_mtw_from_user in the ebtables netfilter subsystem when converting 32-bit user-supplied extension structures to native kernel structures. A local user can provide a crafted match or target size smaller than the extension requires to disclose sensitive information.

The issue affects extensions that rely on compat_from_user callbacks, which assume they can read the required compat size.

Linux kernel
openEuler
Ubuntu
bpftool-debuginfo
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
kernel
linux (Ubuntu package)
linux-ibm (Ubuntu package)
linux-oem-7.0 (Ubuntu package)
linux-aws (Ubuntu package)
linux-azure (Ubuntu package)

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
bpftool-debuginfo - update to 5.10.0-326.0.0.227
python3-perf-debuginfo - update to 5.10.0-326.0.0.227
python3-perf - update to 5.10.0-326.0.0.227
perf-debuginfo - update to 5.10.0-326.0.0.227
perf - update to 5.10.0-326.0.0.227
kernel-tools-devel - update to 5.10.0-326.0.0.227
kernel-tools-debuginfo - update to 5.10.0-326.0.0.227
kernel-tools - update to 5.10.0-326.0.0.227
kernel-source - update to 5.10.0-326.0.0.227
kernel-headers - update to 5.10.0-326.0.0.227
kernel-devel - update to 5.10.0-326.0.0.227
kernel-debugsource - update to 5.10.0-326.0.0.227
kernel-debuginfo - update to 5.10.0-326.0.0.227
bpftool - update to 5.10.0-326.0.0.227
kernel - update to 5.10.0-326.0.0.227
linux (Ubuntu package) - addressed in versions 7.0.0-28.28, 7.0.0-28.28.1, 7.0.0-1003.4, 7.0.0-1008.8
linux-ibm (Ubuntu package) - addressed in versions 7.0.0-1008.8, 7.0.0-1010.10
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1009.9
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

• https://git.kernel.org/stable/c/21af4c030567d2e6c89bb927bc18b51fba52a400
• https://git.kernel.org/stable/c/7ad0e463fc7eafae2141cc38054264636f8b3e94
• https://git.kernel.org/stable/c/a27cb7325a6c69970041c7f8541fafed5a1ea3ec
• https://git.kernel.org/stable/c/bf8e8eac7ede51dc318e06acef5a896dcbba7595
• https://git.kernel.org/stable/c/d7a8fb6f10d55a1c37b0bf8c20cca24dffd76e00
• https://git.kernel.org/stable/c/dad9ebf8107955bb54bd3f9cf22591b6ff37bac1
• https://git.kernel.org/stable/c/f438d1786d657d57790c5d138d6db3fc9fdac392
• https://git.kernel.org/stable/c/fcc4c043d137e7f1de4673dba1f3116e45377c67

• Out-of-bounds read in Linux kernel bridge netfilter
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux
• Ubuntu update for linux-ibm
• Ubuntu update for linux-azure
• Ubuntu update for linux-aws
• openEuler 22.03 LTS SP4 update for kernel