CVE-2022-49271Public exploit

Host crash via zero-length CIFS ioctl buffer

Published Feb 26, 2025 · Updated May 11, 2026

NULL pointer dereference in the Linux kernel CIFS client allows local users to crash the host through a crafted QUERY_INFO ioctl. smb2_ioctl_query_info() accepts a zero output_buffer_length for PASSTHRU_FSCTL, and memdup_user() returns a nonerror zero-size pointer that is later dereferenced. Exploitation requires local access to issue the ioctl against a file on a mounted CIFS share, and a successful trigger crashes the running kernel rather than only the calling process.

CVSS severity5.5
Medium
EPSS probability0.26%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

NULL pointer dereference in the Linux kernel CIFS client allows local users to crash the host through a crafted QUERY_INFO ioctl. smb2_ioctl_query_info() accepts a zero output_buffer_length for PASSTHRU_FSCTL, and memdup_user() returns a nonerror zero-size pointer that is later dereferenced. Exploitation requires local access to issue the ioctl against a file on a mounted CIFS share, and a successful trigger crashes the running kernel rather than only the calling process.

The record

CVE
CVE-2022-49271
Published
Feb 26, 2025
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-476, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 26, 2025CVE publishedPublication date reported by the CVE source.
  2. May 11, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=5.5
  2. Affected versionversion=cfaa1181097f6a1a6f4f6670ebc97848efda0883 <7529fbee10d82493c5cb109e51788bf74816d1c0
  3. Affected versionversion=cfaa1181097f6a1a6f4f6670ebc97848efda0883 <9963ccea6087268e1275b992dca5d0dd4b938765
  4. Affected versionversion=cfaa1181097f6a1a6f4f6670ebc97848efda0883 <b92e358757b91c2827af112cae9af513f26a3f34
  5. Affected versionversion=cfaa1181097f6a1a6f4f6670ebc97848efda0883 <f143f8334fb9eb2f6c7c15b9da1472d9c965fd84
  6. Affected versionversion=cfaa1181097f6a1a6f4f6670ebc97848efda0883 <fadddfc1dc3c6f79b21cff4a7e9a6c40b84fbc53

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.5; version=cfaa1181097f6a1a6f4f6670ebc97848efda0883 <7529fbee10d82493c5cb109e51788bf74816d1c0; version=cfaa1181097f6a1a6f4f6670ebc97848efda0883 <9963ccea6087268e1275b992dca5d0dd4b938765; version=cfaa1181097f6a1a6f4f6670ebc97848efda0883 <b92e358757b91c2827af112cae9af513f26a3f34; version=cfaa1181097f6a1a6f4f6670ebc97848efda0883 <f143f8334fb9eb2f6c7c15b9da1472d9c965fd84; version=cfaa1181097f6a1a6f4f6670ebc97848efda0883 <fadddfc1dc3c6f79b21cff4a7e9a6c40b84fbc53

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-476NULL Pointer Dereference
T1499Endpoint Denial of Service

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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