CVE-2023-52772

Local privilege escalation via AF_UNIX skb race

Published May 21, 2024 · Updated Aug 5, 2026

Use-after-free in Linux kernels from 5.15 on affected stable branches allows local users to escalate privileges through AF_UNIX urgent data. After unix_stream_read_actor releases the socket lock, another thread can replace and free u->oob_skb before the receiver takes an skb reference, leaving the read path to dereference reclaimed kernel memory. Any unprivileged local user can race recvmsg with MSG_OOB and MSG_PEEK against sendmsg on a controlled socket pair, enabling kernel memory access, code execution, or a kernel crash.

CVSS severity7.8
High
EPSS probability0.24%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Use-after-free in Linux kernels from 5.15 on affected stable branches allows local users to escalate privileges through AF_UNIX urgent data. After unix_stream_read_actor releases the socket lock, another thread can replace and free u->oob_skb before the receiver takes an skb reference, leaving the read path to dereference reclaimed kernel memory. Any unprivileged local user can race recvmsg with MSG_OOB and MSG_PEEK against sendmsg on a controlled socket pair, enabling kernel memory access, code execution, or a kernel crash.

The record

CVE
CVE-2023-52772
Published
May 21, 2024
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 21, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 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=5.15
  2. Affected versionversion=876c14ad014d0e39c57cbfde53e13d17cdb6d645 <069a3ec329ff43e7869a3d94c62cd03203016bce
  3. Affected versionversion=876c14ad014d0e39c57cbfde53e13d17cdb6d645 <4b7b492615cf3017190f55444f7016812b66611d
  4. Affected versionversion=876c14ad014d0e39c57cbfde53e13d17cdb6d645 <75bcfc188abf4fae9c1d5f5dc0a03540be602eef
  5. Affected versionversion=876c14ad014d0e39c57cbfde53e13d17cdb6d645 <d179189eec426fe4801e4b91efa1889faed12700
  6. Affected versionversion=876c14ad014d0e39c57cbfde53e13d17cdb6d645 <eae0b295ce16d8c8b4114c3037993191b4bb92f0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.15; version=876c14ad014d0e39c57cbfde53e13d17cdb6d645 <069a3ec329ff43e7869a3d94c62cd03203016bce; version=876c14ad014d0e39c57cbfde53e13d17cdb6d645 <4b7b492615cf3017190f55444f7016812b66611d; version=876c14ad014d0e39c57cbfde53e13d17cdb6d645 <75bcfc188abf4fae9c1d5f5dc0a03540be602eef; version=876c14ad014d0e39c57cbfde53e13d17cdb6d645 <d179189eec426fe4801e4b91efa1889faed12700; version=876c14ad014d0e39c57cbfde53e13d17cdb6d645 <eae0b295ce16d8c8b4114c3037993191b4bb92f0

Published CVSS scores

7.8Linux kernel CNACVSS: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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1068Exploitation for Privilege Escalation

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo