Improper access control in Linux kernel - CVE-2026-53236

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Main Vulnerability Database Vulnerabilities #VU135526

Improper access control in Linux kernel - CVE-2026-53236

Published: June 26, 2026


Vulnerability identifier: #VU135526
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-2026-53236
CWE-ID: CWE-284
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 improper access control in SO_ATTACH_FILTER on TCP sockets when attaching a cBPF filter. A local user can attach a filter to leak TCP sequence and acknowledgment numbers to disclose sensitive information.

Exploitation requires access to create or control a TCP socket and use the socket option interface.


Affected software

Linux kernel
openEuler
Ubuntu
bpftool
kernel
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
linux (Ubuntu package)
linux-azure (Ubuntu package)
linux-gcp-7.0 (Ubuntu package)
linux-oracle-7.0 (Ubuntu package)
linux-oem-7.0 (Ubuntu package)
linux-ibm (Ubuntu package)
linux-azure-7.0 (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-nvidia-7.0 (Ubuntu package)
linux-raspi (Ubuntu package)
linux-nvidia-bos (Ubuntu package)

How to mitigate CVE-2026-53236

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
bpftool - addressed in versions 5.10.0-323.0.0.224, 6.6.0-145.1.20.157
kernel - addressed in versions 5.10.0-323.0.0.224, 6.6.0-145.1.20.157
python3-perf-debuginfo - addressed in versions 5.10.0-323.0.0.224, 6.6.0-145.1.20.157
python3-perf - addressed in versions 5.10.0-323.0.0.224, 6.6.0-145.1.20.157
perf-debuginfo - addressed in versions 5.10.0-323.0.0.224, 6.6.0-145.1.20.157
perf - addressed in versions 5.10.0-323.0.0.224, 6.6.0-145.1.20.157
kernel-tools-devel - addressed in versions 5.10.0-323.0.0.224, 6.6.0-145.1.20.157
kernel-tools-debuginfo - addressed in versions 5.10.0-323.0.0.224, 6.6.0-145.1.20.157
kernel-tools - addressed in versions 5.10.0-323.0.0.224, 6.6.0-145.1.20.157
kernel-source - addressed in versions 5.10.0-323.0.0.224, 6.6.0-145.1.20.157
kernel-headers - addressed in versions 5.10.0-323.0.0.224, 6.6.0-145.1.20.157
kernel-devel - addressed in versions 5.10.0-323.0.0.224, 6.6.0-145.1.20.157
kernel-debugsource - addressed in versions 5.10.0-323.0.0.224, 6.6.0-145.1.20.157
kernel-debuginfo - addressed in versions 5.10.0-323.0.0.224, 6.6.0-145.1.20.157
bpftool-debuginfo - addressed in versions 5.10.0-323.0.0.224, 6.6.0-145.1.20.157
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-azure (Ubuntu package) - addressed in versions 7.0.0-1011.11, 7.0.0-1014.14
linux-gcp-7.0 (Ubuntu package) - update to 7.0.0-1011.11~24.04.1
linux-oracle-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-ibm (Ubuntu package) - update to 7.0.0-1013.13
linux-azure-7.0 (Ubuntu package) - update to 7.0.0-1014.14~24.04.1
linux-nvidia (Ubuntu package) - update to 7.0.0-1018.18
linux-nvidia-7.0 (Ubuntu package) - update to 7.0.0-1018.18~24.04.1
linux-raspi (Ubuntu package) - update to 7.0.0-1019.19
linux-nvidia-bos (Ubuntu package) - update to 7.0.0-2018.18

External References

Related Security Bulletins