CVE-2026-74391

Received Received - Intake

Buffer Overflow in Linux Kernel Tracing Subsystem

Publication date: 2026-08-15

Last updated on: 2026-08-17

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: tracing: Bound synthetic-field strings with seq_buf The synthetic field helpers build a prefixed synthetic variable name and a generated hist command in fixed MAX_FILTER_STR_VAL buffers. The current code appends those strings with raw strcat(), so long key lists, field names, or saved filters can run past the end of the staging buffers. Build both strings with seq_buf and propagate -E2BIG if either the synthetic variable name or the generated command exceeds MAX_FILTER_STR_VAL. This keeps the existing tracing-side limit while using the helper intended for bounded command construction. [ sdr: Moved struct seq_buf *s for upside-down x-mas tree formatting ]

CVSS Scores

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Meta Information

Published

2026-08-15

Last Modified

2026-08-17

Generated

2026-09-04

AI Q&A

2026-08-15

EPSS Evaluated

2026-09-03

NVD

CVE-2026-74391

EUVD

EUVD-2026-59538

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 vulnerability in the Linux kernel involves buffer overflow risks in the tracing subsystem. The issue occurs when synthetic field helpers use strcat() to append strings into fixed-size buffers without proper bounds checking. Long key lists, field names, or saved filters can exceed buffer limits, leading to memory corruption or crashes.

Detection Guidance

This vulnerability is specific to the Linux kernel's tracing subsystem and involves buffer overflows in synthetic-field string handling. Detection requires checking kernel versions and tracing-related configurations. Use commands like 'uname -a' to check kernel version and 'cat /proc/sys/kernel/tracepoint' to inspect tracing settings.

Impact Analysis

If exploited, this flaw could allow an attacker to crash the system, escalate privileges, or execute arbitrary code in the kernel context. It primarily affects systems using the Linux kernel's tracing features with large or complex configurations.

Compliance Impact

This vulnerability does not directly affect compliance with GDPR, HIPAA, or similar standards. It is a Linux kernel issue related to buffer overflow in tracing functionality, which could lead to system instability or crashes but does not involve data exposure or privacy violations.

Mitigation Strategies

Apply the latest kernel patches or updates from your Linux distribution. Disable unnecessary tracing features if not required. Monitor kernel security advisories for updates addressing this issue.

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