# CVE-2026-93811: ksmbd: Fix acl.sd_buf memory leak and invalid sd_size error handling

CVE-2026-93811 is fixed in 2 products on 1 platform, first by DEBIAN-CVE-2026-93811, released September 24, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-93811
- Priority: Routine
- CVSS: 4.4 (Moderate)
- EPSS: 0.0017
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Sep 24, 2026
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-93811

## Description

In the Linux kernel, the following vulnerability has been resolved:  ksmbd: Fix acl.sd_buf memory leak and invalid sd_size error handling  1. When ndr_decode_v4_ntacl() fails, the code jumped to free_n_data    which only freed n.data, skipping kfree(acl.sd_buf) and leaking    the buffer. Zero-initialize struct xattr_ntacl acl, reorder error    labels to out_free to release acl.sd_buf on all error paths.  2. if (acl.sd_size < sizeof(struct smb_ntsd)) is true, original code    returned success without freeing sd_buf and left stale *pntsd.    Set rc = -EINVAL before jumping to out_free to return error code and    free buffer.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | linux Debian 12.15 (bookworm) | 6.1.190-1 | [DEBIAN-CVE-2026-93811](https://patchblox.com/security/data/fix/linux/debian-cve-2026-93811.md) | Sep 24, 2026 |
| Linux | linux Debian 13.5 (trixie) | 6.12.111-1 | [DEBIAN-CVE-2026-93811](https://patchblox.com/security/data/fix/linux/debian-cve-2026-93811.md) | Sep 24, 2026 |
| Linux | linux Debian 14 | 7.2.6-1 | [DEBIAN-CVE-2026-93811](https://patchblox.com/security/data/fix/linux/debian-cve-2026-93811.md) | Sep 24, 2026 |
| Linux | linux-6.12 Debian 12.15 (bookworm) | 6.12.111-1~deb12u1 | [DEBIAN-CVE-2026-93811](https://patchblox.com/security/data/fix/linux/debian-cve-2026-93811.md) | Sep 24, 2026 |

---

Data as of 2026-11-09T19:38:12Z 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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

Free to use with attribution: show "Data: Patchblox Patch Radar" with a link to https://patchblox.com/security/patch-radar. Terms, including what needs a written agreement: https://patchblox.com/security/patch-radar/use-the-data

Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.