CVE-2026-43239

Undergoing Analysis Undergoing Analysis - In Progress

Kernel Race Condition in SMB Client Component

Publication date: 2026-05-06

Last updated on: 2026-05-08

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: smb: client: prevent races in ->query_interfaces() It was possible for two query interface works to be concurrently trying to update the interfaces. Prevent this by checking and updating iface_last_update under iface_lock.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-05-06

Last Modified

2026-05-08

Generated

2026-07-06

AI Q&A

2026-05-06

EPSS Evaluated

2026-07-05

NVD

CVE-2026-43239

EUVD

EUVD-2026-27800

Affected Vendors & Products

Vendor	Product	Version / Range
linux	linux_kernel	*
linux_kernel	linux_kernel	*

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-UNKNOWN

Attack-Flow Graph

Executive Summary

This vulnerability exists in the Linux kernel's SMB client implementation. It involves a race condition in the function responsible for querying interfaces (->query_interfaces()). Specifically, two concurrent query interface operations could attempt to update the interfaces at the same time, leading to potential inconsistencies or unexpected behavior.

The issue was resolved by adding a mechanism to check and update the iface_last_update variable while holding a lock (iface_lock), preventing concurrent updates and thus eliminating the race condition.

Impact Analysis

This vulnerability could lead to race conditions when multiple SMB client queries attempt to update interface information simultaneously. Such race conditions might cause inconsistent or corrupted interface data, potentially resulting in unexpected behavior or instability in SMB client operations on affected Linux systems.

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