# CVE-2026-68457: linux: In the Linux kernel, the following vulnerability has been resolved:  ksmbd: use opener credentials for FSCTL mutation...

CVE-2026-68457 is fixed in linux on 1 platform, first by DEBIAN-CVE-2026-68457, released August 15, 2026. It is not reported as exploited. Patch Radar priority: Urgent.

- Web page: https://patchblox.com/security/cve/CVE-2026-68457
- Priority: Urgent
- CVSS: 9.1 (critical)
- EPSS: 0.0070
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Aug 15, 2026

## Description

In the Linux kernel, the following vulnerability has been resolved:  ksmbd: use opener credentials for FSCTL mutations  SET_SPARSE, SET_ZERO_DATA and SET_COMPRESSION operate on an open SMB handle but call VFS xattr, fallocate or fileattr helpers with the current ksmbd worker credentials. Those helpers can revalidate inode permissions, ownership and LSM policy independently of the SMB handle access mask.  Run each operation with the credentials captured in the target file when the handle was opened. Keep credential handling local to these single-file FSCTLs rather than applying session credentials to the complete IOCTL handler, which also contains handle-less and multi-handle operations.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | linux Debian 12.15 (bookworm) | 6.1.180-1 | [DEBIAN-CVE-2026-68457](https://patchblox.com/security/data/fix/linux/debian-cve-2026-68457.md) | Aug 15, 2026 |
| Linux | linux Debian 13.5 (trixie) | 6.12.100-1 | [DEBIAN-CVE-2026-68457](https://patchblox.com/security/data/fix/linux/debian-cve-2026-68457.md) | Aug 15, 2026 |
| Linux | linux Debian 14 | 7.1.5-1 | [DEBIAN-CVE-2026-68457](https://patchblox.com/security/data/fix/linux/debian-cve-2026-68457.md) | Aug 15, 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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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