SEPTEMBER 17, 2026
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Case File

CVE-2026-74521

CRITICAL · CVSS 9.1 EPSS 0.32%

Source: NVD + CISA KEV + EPSS · Published 2026-08-15 · Last synced 2026-09-14

CyberRota Analysis

AI-Generated

The vulnerability affects the Linux kernel's ksmbd component, where improper comparison of ClientGUIDs using strncmp() can lead to incorrect equality evaluations due to the presence of embedded NUL bytes. This flaw could potentially allow unauthorized access or manipulation of SMB3 multichannel sessions, impacting systems relying on secure file sharing. Organizations utilizing Linux servers with SMB3 functionality should prioritize patching this issue to mitigate potential security risks.

CVE
CVE-2026-74521
Severity
CRITICAL
CVSS
9.1
EPSS
0.32%
Linux

Original NVD Description

In the Linux kernel, the following vulnerability has been resolved: ksmbd: use memcmp() to compare ClientGUIDs ClientGUID is a fixed-size binary value and can contain embedded NUL bytes. strncmp() stops comparing at the first NUL byte, so different ClientGUID values can incorrectly be treated as equal. Use memcmp() in SMB3 multichannel session binding and FSCTL_VALIDATE_NEGOTIATE_INFO to compare all SMB2_CLIENT_GUID_SIZE bytes.