ksmbd: preserve VFS inherited POSIX ACL mask

Answer in brief

CVE-2026-93786 records a High severity (CVSS 8.1) vulnerability in ksmbd: preserve VFS inherited POSIX ACL mask. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 24, 2026Updated Sep 25, 2026Source checked Sep 25, 2026First seen by HOL Sep 25, 2026Material review Sep 25, 2026

Upstream Advisory

Key facts

Risk: High · CVSS 8.1
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

CVSS is 8.1. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Linux/Linuxgeneric	>=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <591acf171644de590cda245fd8595b473a1beb70 \|\| >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <0093909becbda22b62b39b654dbc607faed59cd0 \|\| >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <e148e567a9252643baa125cb65d7ae9c2c6cf68a \|\| >=0 <6.12.111 \|\| >=0 <6.18.53	591acf171644de590cda245fd8595b473a1beb70, 0093909becbda22b62b39b654dbc607faed59cd0, e148e567a9252643baa125cb65d7ae9c2c6cf68a, 6.12.111, 6.18.53

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux.
Review the reported fix. Update Linux/Linux to 591acf171644de590cda245fd8595b473a1beb70 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 24, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 25, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 25, 2026

Sources and claim methodology

Upstream source description

In the Linux kernel, the following vulnerability has been resolved: ksmbd: preserve VFS inherited POSIX ACL mask The VFS initializes a child's POSIX ACL from the parent's default ACL and the requested creation mode. Do not mutate the parent ACL or overwrite the child's VFS-computed access and default ACLs afterwards. This preserves restrictive ACL_MASK entries and prevents SMB object creation from widening effective permissions.

Quoted source text, attributed separately from HOL analysis.