CVE-2026-72236

Received Received - Intake

s390/perf_cpum_cf Speculative Execution in Linux Kernel

Publication date: 2026-08-15

Last updated on: 2026-08-23

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: s390/perf_cpum_cf: Add missing array_index_nospec() to __hw_perf_event_init() ev variable is userspace controlled via event->attr.config and used as an array index after bounds checking, but without speculation barriers. Add the missing array_index_nospec() call to prevent speculative execution.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-08-15

Last Modified

2026-08-23

Generated

2026-09-04

AI Q&A

2026-08-15

EPSS Evaluated

2026-09-03

NVD

CVE-2026-72236

EUVD

EUVD-2026-59135

Affected Vendors & Products

Vendor	Product	Version / Range
linux	linux_kernel	*

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-UNKNOWN

Attack-Flow Graph

Executive Summary

This is a speculative execution vulnerability in the Linux kernel's s390/perf_cpum_cf subsystem. A user-controlled variable 'ev' derived from event->attr.config is used as an array index without proper speculation barriers after bounds checking. This allows potential information disclosure through speculative execution attacks.

Detection Guidance

This vulnerability is specific to the Linux kernel's s390/perf_cpum_cf subsystem and requires kernel-level access to detect. Check if your kernel version includes the fix by running uname -a and comparing against patched versions. Monitor system logs for suspicious perf event configurations.

Impact Analysis

This vulnerability could allow an attacker with local access to potentially leak sensitive kernel memory contents through speculative execution side channels. It requires local user access to trigger but could expose system memory to unauthorized parties.

Compliance Impact

This vulnerability does not directly affect compliance with standards like GDPR or HIPAA. It is a low-level kernel issue related to speculative execution and array bounds checking, which does not involve data exposure or privacy violations typically addressed by these regulations.

Mitigation Strategies

Apply the latest kernel patches from your Linux distribution. If patches are unavailable, disable the s390/perf_cpum_cf subsystem by blacklisting related kernel modules or restricting access to perf_event_open system calls.

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