---
id: "CVE-2026-98452"
kind: "vulnerability"
aliases: ["CVE-2026-98452"]
title: "Linux kernel SMB client: failed cached directory opens leak handles and mishandle responses"
severity: "unknown"
cvss: null
epss: null
exploited: false
status: "open"
category: "runtime"
products: []
ecosystems: []
tags: ["cifs", "linux-kernel", "runtime", "smb-client"]
not_affected_if: ["no-smb-mounts"]
published_at: "2026-10-18T16:16:55+00:00"
first_seen_at: "2026-10-23T21:57:15+00:00"
updated_at: "2026-10-25T05:27:23+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-98452", "first_seen_at": "2026-10-23T21:57:15+00:00"}]
---

# Linux kernel SMB client: failed cached directory opens leak handles and mishandle responses

The Linux kernel's SMB client (cifs/smb3) could keep a CREATE file handle open when a later command in the same compound request failed, and could trust a failed CREATE response. The sources do not describe a confirmed attacker path, so the practical impact is unknown.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Run `uname -r` and compare against the kernel version that carries the fix, see the advisory at https://nvd.nist.gov/vuln/detail/CVE-2026-98452
- Check whether the SMB client is in use with `lsmod | grep -E 'cifs|smb'` or `mount -t cifs,smb3`

## Fix

- Update the Linux kernel to a release that includes the upstream commit for CVE-2026-98452; the fixed version is unknown in the sources
- Until patched, avoid mounting untrusted SMB shares

## Timeline

- 2026-10-23T21:57:15+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-98452

## From the sources

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

smb: client: clean up failed cached directory opens

open_cached_dir() sends CREATE and QUERY_INFO as a compound request. If
the CREATE succeeds but a later command returns an error, the function
must retain the CREATE FID so common cleanup can issue SMB2_close(). It
also must not treat a response error as a valid CREATE.

Validate the CREATE response before using its fields, record the FIDs, and
mark the handle open before handling errors from later compound commands.
Move the -EREMCHG reconnect handling before response validation so a
missing response does not hide the reconnect request. Count the handle
when it is marked open; confirmed close responses decrement the counter,
while existing close retry behavior remains best effort on transport
failures.

---

_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_