CVE-2023-53781

Kernel memory corruption via lingering SMC TCP timers

Published Dec 9, 2025 · Updated Aug 5, 2026

Use-after-free in Linux kernel 4.11 through 6.2.11 allows local users to corrupt kernel memory and crash the system. The SMC close path releases a kernel socket while its TCP state can remain open, leaving timers able to access the freed network namespace. Exploitation requires a local low-privileged user to create AF_SMC sockets and a disposable user network namespace; timer execution can disclose or corrupt kernel memory and cause an oops or panic.

CVSS severity7.8
High
EPSS probability0.14%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in Linux kernel 4.11 through 6.2.11 allows local users to corrupt kernel memory and crash the system. The SMC close path releases a kernel socket while its TCP state can remain open, leaving timers able to access the freed network namespace. Exploitation requires a local low-privileged user to create AF_SMC sockets and a disposable user network namespace; timer execution can disclose or corrupt kernel memory and cause an oops or panic.

The record

CVE
CVE-2023-53781
Published
Dec 9, 2025
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 9, 2025CVE 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

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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=4.11
  2. Affected versionversion=ac7138746e14137a451f8539614cdd349153e0c0 <1cc41c8acfc1ee30b4868559058db97fa44b0137
  3. Affected versionversion=ac7138746e14137a451f8539614cdd349153e0c0 <9744d2bf19762703704ecba885b7ac282c02eacf

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4.11; version=ac7138746e14137a451f8539614cdd349153e0c0 <1cc41c8acfc1ee30b4868559058db97fa44b0137; version=ac7138746e14137a451f8539614cdd349153e0c0 <9744d2bf19762703704ecba885b7ac282c02eacf

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.

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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)
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

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Your stack

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