CVE-2023-3867Network attack vector

Kernel-memory disclosure via compound session setup

Published Aug 16, 2025 · Updated Aug 15, 2026

Out-of-bounds read in Linux kernel ksmbd allows remote attackers to disclose kernel memory through a crafted SMB2 compound request. smb2_sess_setup() derives request and response structures from the first compound payload instead of the current session-setup payload, causing reads past the allocated buffer. Network access to port 445 and an enabled ksmbd server are sufficient; the bounded direct impacts are kernel-memory disclosure and service interruption.

CVSS severity9.1
Critical
EPSS probability5.37%
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 allows remote attackers to disclose kernel memory through a crafted SMB2 compound request. smb2_sess_setup() derives request and response structures from the first compound payload instead of the current session-setup payload, causing reads past the allocated buffer. Network access to port 445 and an enabled ksmbd server are sufficient; the bounded direct impacts are kernel-memory disclosure and service interruption.

The record

CVE
CVE-2023-3867
Published
Aug 16, 2025
Updated
Aug 15, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-125, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 16, 2025CVE publishedPublication date reported by the CVE source.
  2. Aug 15, 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=5.15
  2. Affected versionversion=e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 <2ba03cecb12ac7ac9e0170e251543c56832d9959
  3. Affected versionversion=e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 <676392184785ace61e939831e7ca44a03d438c3b
  4. Affected versionversion=e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 <98422bdd4cb3ca4d08844046f6507d7ec2c2b8d8
  5. Affected versionversion=e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 <ef572ffa8eb44111eed2925fbb2adca78bdcbf61

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.15; version=e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 <2ba03cecb12ac7ac9e0170e251543c56832d9959; version=e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 <676392184785ace61e939831e7ca44a03d438c3b; version=e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 <98422bdd4cb3ca4d08844046f6507d7ec2c2b8d8; version=e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 <ef572ffa8eb44111eed2925fbb2adca78bdcbf61

Published CVSS scores

7.1NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
9.1Linux kernel CVE teamCVSS:3.1/AV:N/AC:L/PR:N/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-125Out-of-bounds Read
T1190Exploit Public-Facing Application

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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