Linux Kernel NFS client Vulnerability Rated 7.6 CVSS

Last refreshed2026-10-15

Status: UPDATED | Advisory ID: CVE-2026-43350

Key Details

CVE	CVE-2026-43350
CVSS Score / Version	7.6 (High) / CVSS v3.1
Updated	2026-10-15
CVSS Vector	`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H`
CVSS Prose	attack vector is network; attack complexity is low; privileges required is none; user interaction is required; scope is unchanged; confidentiality impact is low; integrity impact is low; availability impact is high.
Affected products	Linux Kernel and Siemens SIMATIC S7-1500 TM MFP - GNU/Linux subsystem
Exploitation prediction (EPSS)	0.26% probability of exploitation in the next 30 days (16% percentile) -- FIRST.org's EPSS model.

Vendor	Product	Affected Versions	Patch Status
Linux	Linux Kernel
Siemens	SIMATIC S7-1500 TM MFP - GNU/Linux subsystem

Vendor

Product

Affected Versions

Patch Status

Linux

Linux Kernel

Siemens

SIMATIC S7-1500 TM MFP - GNU/Linux subsystem

Subsystems	Controllers & Field I/O, OT Supporting Infrastructure
Sectors	All Sectors

In the Linux kernel, the following vulnerability has been resolved:

smb: client: require a full NFS mode SID before reading mode bits

parse_dacl() treats an ACE SID matching sid_unix_NFS_mode as an NFS

mode SID and reads sid.sub_auth[2] to recover the mode bits.

That assumes the ACE carries three subauthorities, but compare_sids()

only compares min(a, b) subauthorities. A malicious server can return

an ACE with num_subauth = 2 and sub_auth[] = {88, 3}, which still

matches sid_unix_NFS_mode and then drives the sub_auth[2] read four

bytes past the end of the ACE.

Require num_subauth >= 3 before treating the ACE as an NFS mode SID.

This keeps the fix local to the special-SID mode path without changing

compare_sids() semantics for the rest of cifsacl. (NVD)

Monitor Linux's and Siemens's web pages for any future patch releases.

Source	Reference
NVD	https://nvd.nist.gov/vuln/detail/CVE-2026-43350
CVE	https://www.cve.org/CVERecord?id=CVE-2026-43350

Source

Reference

NVD

CVE