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CVE-2026-64395VulnerabilityPublished 07/25/2026

In the Linux kernel, the following vulnerability has been resolved: ksmbd: require source read access for duplicate…

Source GCVE Database

0

Not known to be exploited.

Data as of 10/24/2026, 22:16:04 UTC

Severity
High

No CVSS score from NVD or the CNA

Exploitation

Not in CISA KEV, no exploitation reported

EPSS
0.4% chance of exploitation in 30 days – higher than 33% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

What to do

AI-suggested

A fix has been implemented in the Linux kernel to require FILE_READ_DATA permission on the source handle before performing duplicate extent copy operations in ksmbd. Users should apply the official kernel updates that include this fix. Patch status is not explicitly confirmed in the provided data; therefore, check the vendor advisory or Linux kernel release notes for the specific patch and update accordingly.

Description

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.

Impact

An attacker with a handle opened with attribute-only access could copy file contents to an attacker-readable destination, potentially exposing sensitive data. This bypasses intended access controls on the source file, leading to unauthorized data disclosure.

References

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