# CVE-2026-68097: ksmbd: validate ACE size against SID sub-authorities

CVE-2026-68097 is fixed in 2 products on 1 platform, first by DEBIAN-CVE-2026-68097, released August 11, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-68097
- Priority: High
- CVSS: 8.8 (Moderate)
- EPSS: 0.0045
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Aug 10, 2026
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-68097

## Description

In the Linux kernel, the following vulnerability has been resolved:  ksmbd: validate ACE size against SID sub-authorities  set_ntacl_dacl() validates sid.num_subauth before copying an ACE, but does not verify that the declared ACE size contains all sub-authorities described by that field. An undersized ACE can therefore be copied and later make the POSIX ACL deduplication walk inspect data beyond the copied ACE boundary.  The existing initial bound check is also too small. It only ensures that the ACE size field is accessible before set_ntacl_dacl() reads sid.num_subauth farther into the input buffer.  Require enough input for the fixed SID header before accessing num_subauth, reject ACEs smaller than that header, and skip ACEs whose declared size cannot contain the complete SID. This makes the validation consistent with the other ACE walk paths.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | linux Debian 12.15 (bookworm) | 6.1.190-1 | [DEBIAN-CVE-2026-68097](https://patchblox.com/security/data/fix/linux/debian-cve-2026-68097.md) | Aug 11, 2026 |
| Linux | linux Debian 13.5 (trixie) | 6.12.101-1 | [DEBIAN-CVE-2026-68097](https://patchblox.com/security/data/fix/linux/debian-cve-2026-68097.md) | Aug 11, 2026 |
| Linux | linux Debian 14 | 7.1.6-1 | [DEBIAN-CVE-2026-68097](https://patchblox.com/security/data/fix/linux/debian-cve-2026-68097.md) | Aug 11, 2026 |
| Linux | linux-6.12 Debian 12.15 (bookworm) | 6.12.101-1~deb12u1 | [DEBIAN-CVE-2026-68097](https://patchblox.com/security/data/fix/linux/debian-cve-2026-68097.md) | Aug 11, 2026 |

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Data as of 2026-11-08T00:53:09Z 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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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