CVE Catalog

CVE-2026-64395

HighCVSS 7.5
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.41%

34th percentile - higher than 34% of all known CVEs

Summary

In the Linux kernel, the ksmbd filesystem lacks a read permission check for the source file during the duplicate extents operation (FSCTL_DUPLICATE_EXTENTS_TO_FILE). A handle opened only with attribute access can be used to copy file contents to an attacker-readable destination.

Risk Assessment

An attacker can read file contents without proper permissions, leading to sensitive data leakage.

Recommendation

Apply the Linux kernel patch that adds a FILE_READ_DATA permission requirement for the source handle before the duplicate extents operation.

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: ksmbd: require source read access for duplicate extents FSCTL_DUPLICATE_EXTENTS_TO_FILE passes the source file directly to vfs_clone_file_range() or vfs_copy_file_range() without checking the SMB access mask granted to the source handle. A handle opened with attribute access can consequently be used to copy file contents into an attacker-readable destination. Require FILE_READ_DATA on the source handle before either VFS operation, matching other ksmbd data-copy paths.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS