CVE-2022-49587

Service interruption via unsynchronized TCP sysctl read

Published Feb 26, 2025 · Updated May 11, 2026

A race condition in Linux kernel TCP code allows local users to interrupt service by racing a shared sysctl read. The tcp_notsent_lowat helper in include/net/tcp.h reads sysctl_tcp_notsent_lowat without READ_ONCE while a concurrent sysctl write can change it. Exploitation requires low-privilege local access and favorable race timing; public records establish availability impact but do not identify a specific hang, crash, or reboot outcome.

CVSS severity4.7
Medium
EPSS probability0.19%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

A race condition in Linux kernel TCP code allows local users to interrupt service by racing a shared sysctl read. The tcp_notsent_lowat helper in include/net/tcp.h reads sysctl_tcp_notsent_lowat without READ_ONCE while a concurrent sysctl write can change it. Exploitation requires low-privilege local access and favorable race timing; public records establish availability impact but do not identify a specific hang, crash, or reboot outcome.

The record

CVE
CVE-2022-49587
Published
Feb 26, 2025
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-362, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 26, 2025CVE publishedPublication date reported by the CVE source.
  2. May 11, 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=3.12
  2. Affected versionversion=c9bee3b7fdecb0c1d070c7b54113b3bdfb9a3d36 <0f75343584ee474303e17efe0610bdd170af1d13
  3. Affected versionversion=c9bee3b7fdecb0c1d070c7b54113b3bdfb9a3d36 <55be873695ed8912eb77ff46d1d1cadf028bd0f3
  4. Affected versionversion=c9bee3b7fdecb0c1d070c7b54113b3bdfb9a3d36 <62e56cfeb2ae4b53ae9ca24c80f54093250ce64a
  5. Affected versionversion=c9bee3b7fdecb0c1d070c7b54113b3bdfb9a3d36 <80d4d0c461674eea87f0977e12a2ecd334b9b79c
  6. Affected versionversion=c9bee3b7fdecb0c1d070c7b54113b3bdfb9a3d36 <91e21df688f8a75255ca9c459da39ac96300113a
  7. Affected versionversion=c9bee3b7fdecb0c1d070c7b54113b3bdfb9a3d36 <c1b85c5a34294f7444c13bf828e0e84b0a0eed85
  8. Affected versionversion=c9bee3b7fdecb0c1d070c7b54113b3bdfb9a3d36 <e9362a993886613ef0284c2a4911c6017c97d803
  9. Affected versionversion=c9bee3b7fdecb0c1d070c7b54113b3bdfb9a3d36 <fd6f1284e380c377932186042ff0b5c987fb2b92

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=3.12; version=c9bee3b7fdecb0c1d070c7b54113b3bdfb9a3d36 <0f75343584ee474303e17efe0610bdd170af1d13; version=c9bee3b7fdecb0c1d070c7b54113b3bdfb9a3d36 <55be873695ed8912eb77ff46d1d1cadf028bd0f3; version=c9bee3b7fdecb0c1d070c7b54113b3bdfb9a3d36 <62e56cfeb2ae4b53ae9ca24c80f54093250ce64a; version=c9bee3b7fdecb0c1d070c7b54113b3bdfb9a3d36 <80d4d0c461674eea87f0977e12a2ecd334b9b79c; version=c9bee3b7fdecb0c1d070c7b54113b3bdfb9a3d36 <91e21df688f8a75255ca9c459da39ac96300113a; version=c9bee3b7fdecb0c1d070c7b54113b3bdfb9a3d36 <c1b85c5a34294f7444c13bf828e0e84b0a0eed85; version=c9bee3b7fdecb0c1d070c7b54113b3bdfb9a3d36 <e9362a993886613ef0284c2a4911c6017c97d803; version=c9bee3b7fdecb0c1d070c7b54113b3bdfb9a3d36 <fd6f1284e380c377932186042ff0b5c987fb2b92

Published CVSS scores

4.7NIST NVDCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/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

CWE-362Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
T1499.004Application or System Exploitation

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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