CVE-2023-52441Network attack vector

Kernel-heap disclosure via SMB dialect confusion

Published Feb 21, 2024 · Updated Aug 15, 2026

Out-of-bounds read in Linux ksmbd allows remote attackers to disclose kernel-heap data through pre-authentication SMB negotiation. After an SMB2 negotiate clears need_neg, a following SMB1 negotiate reaches init_smb2_rsp_hdr(), which copies header fields beyond the attacker-sized request buffer into the response. Only hosts running ksmbd on TCP port 445 are exposed; the unauthenticated sequence can disclose kernel memory or trigger a kernel panic, without an integrity primitive from this flaw alone.

CVSS severity9.1
Critical
EPSS probability0.68%
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 allows remote attackers to disclose kernel-heap data through pre-authentication SMB negotiation. After an SMB2 negotiate clears need_neg, a following SMB1 negotiate reaches init_smb2_rsp_hdr(), which copies header fields beyond the attacker-sized request buffer into the response. Only hosts running ksmbd on TCP port 445 are exposed; the unauthenticated sequence can disclose kernel memory or trigger a kernel panic, without an integrity primitive from this flaw alone.

The record

CVE
CVE-2023-52441
Published
Feb 21, 2024
Updated
Aug 15, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-119, T1210
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 21, 2024CVE 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

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=0b3ec5671ac06829ccebdaeec05acedfec327f42 <330d900620dfc9893011d725b3620cd2ee0bc2bc
  2. Affected versionversion=39b291b86b5988bf8753c3874d5c773399d09b96 <536bb492d39bb6c080c92f31e8a55fe9934f452b
  3. Affected versionversion=39b291b86b5988bf8753c3874d5c773399d09b96 <aa669ef229ae8dd779da9caa24e254964545895f
  4. Affected versionversion=5.15.105 <5.15.145
  5. Affected versionversion=51a8534c0f35c0401e45f1055f914729cad98bf9 <5c0df9d30c289d6b9d7d44e2a450de2f8e3cf40b
  6. Affected versionversion=6.1.22 <6.1.53
  7. Affected versionversion=6.2.9 <6.3
  8. Affected versionversion=6.3
  9. Affected versionversion=cc32cd98a0aee4cc3eb611cbce11795b1aaa738a

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=0b3ec5671ac06829ccebdaeec05acedfec327f42 <330d900620dfc9893011d725b3620cd2ee0bc2bc; version=39b291b86b5988bf8753c3874d5c773399d09b96 <536bb492d39bb6c080c92f31e8a55fe9934f452b; version=39b291b86b5988bf8753c3874d5c773399d09b96 <aa669ef229ae8dd779da9caa24e254964545895f; version=5.15.105 <5.15.145; version=51a8534c0f35c0401e45f1055f914729cad98bf9 <5c0df9d30c289d6b9d7d44e2a450de2f8e3cf40b; version=6.1.22 <6.1.53; version=6.2.9 <6.3; version=6.3; version=cc32cd98a0aee4cc3eb611cbce11795b1aaa738a

Published CVSS scores

8.6Trend Micro Zero Day InitiativeCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N
9.1Linux CNACVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-119Improper Restriction of Operations within the Bounds of a Memory Buffer
T1210Exploitation of Remote Services

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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