CVE-2022-49601

Local service interruption via unsynchronized fwmark read

Published Feb 26, 2025 · Updated May 11, 2026

A race condition in affected Linux kernel releases allows local users to interrupt service during TCP or DCCP connection handling. The inet_request_mark function reads the sysctl_tcp_fwmark_accept setting without READ_ONCE while another execution context can change it. The race requires local low-privilege access and precise timing; the documented consequence is limited to service interruption.

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 affected Linux kernel releases allows local users to interrupt service during TCP or DCCP connection handling. The inet_request_mark function reads the sysctl_tcp_fwmark_accept setting without READ_ONCE while another execution context can change it. The race requires local low-privilege access and precise timing; the documented consequence is limited to service interruption.

The record

CVE
CVE-2022-49601
Published
Feb 26, 2025
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-362, T1499
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

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=3.16
  2. Affected versionversion=84f39b08d7868ce10eeaf640627cb89777f0ae93 <13207f9485b5de68decf296ceb0046f5eabb2485
  3. Affected versionversion=84f39b08d7868ce10eeaf640627cb89777f0ae93 <1a0008f9df59451d0a17806c1ee1a19857032fa8
  4. Affected versionversion=84f39b08d7868ce10eeaf640627cb89777f0ae93 <45fc82706a97242539d6b841ddd7a077ec20757b
  5. Affected versionversion=84f39b08d7868ce10eeaf640627cb89777f0ae93 <526d8cf8824f613c72dba2155542295e70135f62
  6. Affected versionversion=84f39b08d7868ce10eeaf640627cb89777f0ae93 <a7386602a2fe2f6192477e8ede291a815da09d81
  7. Affected versionversion=84f39b08d7868ce10eeaf640627cb89777f0ae93 <abf70de2ec026ae8d7da4e79bec61888a880e00b
  8. Affected versionversion=84f39b08d7868ce10eeaf640627cb89777f0ae93 <bf3134feffe61b7a0e21f60a04743f8da0958b53
  9. Affected versionversion=84f39b08d7868ce10eeaf640627cb89777f0ae93 <d4f65615db7fca3df9f7e79eadf937e6ddb03c54

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=3.16; version=84f39b08d7868ce10eeaf640627cb89777f0ae93 <13207f9485b5de68decf296ceb0046f5eabb2485; version=84f39b08d7868ce10eeaf640627cb89777f0ae93 <1a0008f9df59451d0a17806c1ee1a19857032fa8; version=84f39b08d7868ce10eeaf640627cb89777f0ae93 <45fc82706a97242539d6b841ddd7a077ec20757b; version=84f39b08d7868ce10eeaf640627cb89777f0ae93 <526d8cf8824f613c72dba2155542295e70135f62; version=84f39b08d7868ce10eeaf640627cb89777f0ae93 <a7386602a2fe2f6192477e8ede291a815da09d81; version=84f39b08d7868ce10eeaf640627cb89777f0ae93 <abf70de2ec026ae8d7da4e79bec61888a880e00b; version=84f39b08d7868ce10eeaf640627cb89777f0ae93 <bf3134feffe61b7a0e21f60a04743f8da0958b53; version=84f39b08d7868ce10eeaf640627cb89777f0ae93 <d4f65615db7fca3df9f7e79eadf937e6ddb03c54

Published CVSS scores

4.7CISA-ADPCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
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.

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

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 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')
T1499Endpoint Denial of Service

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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