# CVE-2026-64395: linux: In the Linux kernel, the following vulnerability has been resolved:  ksmbd: require source read access for duplicate...

CVE-2026-64395 is fixed in 2 products on 1 platform, first by DEBIAN-CVE-2026-64395, released July 26, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-64395
- Priority: High
- CVSS: 7.5 (high)
- EPSS: 0.0041
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Jul 25, 2026

## 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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | linux Debian 12.15 (bookworm) | 6.1.180-1 | [DEBIAN-CVE-2026-64395](https://patchblox.com/security/data/fix/linux/debian-cve-2026-64395.md) | Jul 26, 2026 |
| Linux | linux Debian 13.5 (trixie) | 6.12.96-1 | [DEBIAN-CVE-2026-64395](https://patchblox.com/security/data/fix/linux/debian-cve-2026-64395.md) | Jul 26, 2026 |
| Linux | linux Debian 14 | 7.1.4-1 | [DEBIAN-CVE-2026-64395](https://patchblox.com/security/data/fix/linux/debian-cve-2026-64395.md) | Jul 26, 2026 |
| Linux | linux-6.12 Debian 12.15 (bookworm) | 6.12.100-1~deb12u1 | [DEBIAN-CVE-2026-64395](https://patchblox.com/security/data/fix/linux/debian-cve-2026-64395.md) | Jul 26, 2026 |

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Data as of 2026-11-09T01:18:40Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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