CVE-2022-47940Network attack vector

Kernel memory disclosure via unchecked SMB2 WRITE length

Published Dec 23, 2022 · Updated Apr 14, 2025

Out-of-bounds read in Linux kernel ksmbd 5.15 through 5.18 before 5.18.18 allows remote authenticated users to read kernel memory. In smb2_write, the non-padding path accepts an SMB2 WRITE DataOffset and Length without checking that their sum stays within the received request buffer. A valid SMB session and writable share are required; the over-read can disclose kernel memory or crash the host.

CVSS severity8.1
High
EPSS probability1.39%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds read in Linux kernel ksmbd 5.15 through 5.18 before 5.18.18 allows remote authenticated users to read kernel memory. In smb2_write, the non-padding path accepts an SMB2 WRITE DataOffset and Length without checking that their sum stays within the received request buffer. A valid SMB session and writable share are required; the over-read can disclose kernel memory or crash the host.

The record

CVE
CVE-2022-47940
Published
Dec 23, 2022
Updated
Apr 14, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-125, T1005
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 23, 2022CVE publishedPublication date reported by the CVE source.
  2. Apr 14, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

8.1CISA-ADPCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
8.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/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)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-125Out-of-bounds Read
T1005Data from Local System

Public exploit references

No public exploit references are available in this record.

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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