CVE-2023-54250Network attack vector

Kernel disclosure and crash via SMB2 bounds check

Published Dec 30, 2025 · Updated Dec 30, 2025

Out-of-bounds read in Linux ksmbd 5.15 through 6.2 allows remote attackers to disclose kernel data or crash the host via SMB2 negotiation. decode_preauth_ctxt() reads the client-controlled HashAlgorithms field after deassemble_neg_contexts() validates only the eight-byte context header plus DataLength, leaving the field outside the request boundary. Any host able to reach TCP port 445 can send the pre-authentication request without credentials; the two-byte read acts as a bounded heap oracle and can trigger a kernel oops or panic.

CVSS severity8.2
High
EPSS probability0.47%
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 ksmbd 5.15 through 6.2 allows remote attackers to disclose kernel data or crash the host via SMB2 negotiation. decode_preauth_ctxt() reads the client-controlled HashAlgorithms field after deassemble_neg_contexts() validates only the eight-byte context header plus DataLength, leaving the field outside the request boundary. Any host able to reach TCP port 445 can send the pre-authentication request without credentials; the two-byte read acts as a bounded heap oracle and can trigger a kernel oops or panic.

The record

CVE
CVE-2023-54250
Published
Dec 30, 2025
Updated
Dec 30, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 30, 2025CVE publishedPublication date reported by the CVE source.
  2. Dec 30, 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?

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

  1. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <39f5b4b313b445c980a2a295bed28228c29228ed
  2. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <a2f6ded41bec1d3be643c80a5eb97f1680309001
  3. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <e7067a446264a7514fa1cfaa4052cdb6803bc6a2
  4. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <f02edb9debbd36f44efa7567031485892c7df60d

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <39f5b4b313b445c980a2a295bed28228c29228ed; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <a2f6ded41bec1d3be643c80a5eb97f1680309001; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <e7067a446264a7514fa1cfaa4052cdb6803bc6a2; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <f02edb9debbd36f44efa7567031485892c7df60d

Published CVSS scores

8.2LinuxCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

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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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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