SEPTEMBER 17, 2026
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Case File

CVE-2026-64397

CRITICAL · CVSS 9.8 EPSS 0.48%

Source: NVD + CISA KEV + EPSS · Published 2026-07-25 · Last synced 2026-08-24

CyberRota Analysis

AI-Generated

The vulnerability affects the Linux kernel's ksmbd component, specifically in the handling of concurrent QUERY_DIRECTORY requests that can lead to a stack use-after-free condition. This flaw allows attackers to exploit the race condition, potentially leading to arbitrary code execution or system crashes. Organizations using Linux systems that rely on the ksmbd file server should prioritize patching this critical vulnerability to mitigate the risk of exploitation.

CVE
CVE-2026-64397
Severity
CRITICAL
CVSS
9.8
EPSS
0.48%
Linux

Original NVD Description

In the Linux kernel, the following vulnerability has been resolved: ksmbd: serialize QUERY_DIRECTORY requests per file smb2_query_dir() stores a pointer to its stack-allocated private data in the ksmbd_file readdir_data. Concurrent QUERY_DIRECTORY requests using the same file handle can overwrite this pointer while an iterate_dir() callback is still using it, resulting in a stack use-after-free. Add a per-file mutex and hold it while accessing the shared directory enumeration state. The lock covers scan restart, dot entry state, readdir_data setup and iteration, and response construction. This prevents another request from replacing readdir_data.private before the current request has finished using it and also serializes the shared file position.