CVE-2023-52480Network attack vector

Unauthenticated kernel compromise via session use-after-free

Published Feb 29, 2024 · Updated Aug 15, 2026

A use-after-free in Linux ksmbd allows remote attackers to compromise the kernel through concurrent unauthenticated SMB requests. ksmbd_session_lookup updates last_active after another worker can erase and free the same session during SMB2 SESSION_SETUP expiration. Exploitation requires ksmbd to listen on TCP port 445; successful races expose kernel memory, enable ring-0 control-flow hijacking, or panic the host.

CVSS severity9.8
Critical
EPSS probability0.48%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

A use-after-free in Linux ksmbd allows remote attackers to compromise the kernel through concurrent unauthenticated SMB requests. ksmbd_session_lookup updates last_active after another worker can erase and free the same session during SMB2 SESSION_SETUP expiration. Exploitation requires ksmbd to listen on TCP port 445; successful races expose kernel memory, enable ring-0 control-flow hijacking, or panic the host.

The record

CVE
CVE-2023-52480
Published
Feb 29, 2024
Updated
Aug 15, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-362, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 29, 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=1fc8a2b14ef5223f8e0b95faba2ee0a6e4d0f99d <a2ca5fd3dbcc665e1169044fa0c9e3eba779202b
  2. Affected versionversion=6.1.29 <6.1.57
  3. Affected versionversion=6.2.16 <6.3
  4. Affected versionversion=6.3.2 <6.4
  5. Affected versionversion=6.4
  6. Affected versionversion=6775ee7ef4b37c521aa4cf3730f54554c4875542
  7. Affected versionversion=750a2d772e9d9ff377fd32e3b6797bf2cd847a7a
  8. Affected versionversion=a6a9601ba995d0fec635324cb9fd8d14f9bea14e <c77fd3e25a51ac92b0f1b347a96eff6a0b4f066f
  9. Affected versionversion=ea174a91893956450510945a0c5d1a10b5323656 <18ced78b0ebccc2d16f426143dc56ab3aad666be
  10. Affected versionversion=ea174a91893956450510945a0c5d1a10b5323656 <53ff5cf89142b978b1a5ca8dc4d4425e6a09745f

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=1fc8a2b14ef5223f8e0b95faba2ee0a6e4d0f99d <a2ca5fd3dbcc665e1169044fa0c9e3eba779202b; version=6.1.29 <6.1.57; version=6.2.16 <6.3; version=6.3.2 <6.4; version=6.4; version=6775ee7ef4b37c521aa4cf3730f54554c4875542; version=750a2d772e9d9ff377fd32e3b6797bf2cd847a7a; version=a6a9601ba995d0fec635324cb9fd8d14f9bea14e <c77fd3e25a51ac92b0f1b347a96eff6a0b4f066f; version=ea174a91893956450510945a0c5d1a10b5323656 <18ced78b0ebccc2d16f426143dc56ab3aad666be; version=ea174a91893956450510945a0c5d1a10b5323656 <53ff5cf89142b978b1a5ca8dc4d4425e6a09745f

Published CVSS scores

7.0NISTCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
9.8Linux Kernel CNACVSS:3.1/AV:N/AC:L/PR:N/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-362Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
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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