CVE-2022-49372

Local service interruption via preemptible per-CPU counters

Published Feb 26, 2025 · Updated May 11, 2026

Improper per-CPU counter access in the Linux kernel allows local users to interrupt service during TCP Fast Open SYN-ACK retransmission. When release_sock processes a queued SYN retransmission in process context, tcp_rtx_synack uses counter helpers that assume preemption is disabled. Reaching the fault requires CONFIG_DEBUG_PREEMPT, a passive Fast Open socket, a concurrent socket operation, and a retransmitted SYN; the reported result is a kernel BUG and availability loss.

CVSS severity5.5
Medium
EPSS probability0.29%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper per-CPU counter access in the Linux kernel allows local users to interrupt service during TCP Fast Open SYN-ACK retransmission. When release_sock processes a queued SYN retransmission in process context, tcp_rtx_synack uses counter helpers that assume preemption is disabled. Reaching the fault requires CONFIG_DEBUG_PREEMPT, a passive Fast Open socket, a concurrent socket operation, and a retransmitted SYN; the reported result is a kernel BUG and availability loss.

The record

CVE
CVE-2022-49372
Published
Feb 26, 2025
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
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=168a8f58059a22feb9e9a2dcc1b8053dbbbc12ef <0a0f7f84148445c9f02f226928803a870139d820
  2. Affected versionversion=168a8f58059a22feb9e9a2dcc1b8053dbbbc12ef <0a375c822497ed6ad6b5da0792a12a6f1af10c0b
  3. Affected versionversion=168a8f58059a22feb9e9a2dcc1b8053dbbbc12ef <3db889f883e65bbd3b1401279bfc1e9ed255c481
  4. Affected versionversion=168a8f58059a22feb9e9a2dcc1b8053dbbbc12ef <58bd38cbc961fd799842b7be8c5222310f04b908
  5. Affected versionversion=168a8f58059a22feb9e9a2dcc1b8053dbbbc12ef <88cd232146207ff1d41dededed5e77c0d4438113
  6. Affected versionversion=168a8f58059a22feb9e9a2dcc1b8053dbbbc12ef <bdc28a8fb43cc476e33b11519235adb816ce00e8
  7. Affected versionversion=168a8f58059a22feb9e9a2dcc1b8053dbbbc12ef <c348b0f8d035fc4bdc040796889beec7218bd1b8
  8. Affected versionversion=168a8f58059a22feb9e9a2dcc1b8053dbbbc12ef <d05c2fdf8e10528bb6751bd95243e862d5402a9b
  9. Affected versionversion=168a8f58059a22feb9e9a2dcc1b8053dbbbc12ef <d8e1bc6029acac796293310aacef7b7336f35b6a
  10. Affected versionversion=3.7

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=168a8f58059a22feb9e9a2dcc1b8053dbbbc12ef <0a0f7f84148445c9f02f226928803a870139d820; version=168a8f58059a22feb9e9a2dcc1b8053dbbbc12ef <0a375c822497ed6ad6b5da0792a12a6f1af10c0b; version=168a8f58059a22feb9e9a2dcc1b8053dbbbc12ef <3db889f883e65bbd3b1401279bfc1e9ed255c481; version=168a8f58059a22feb9e9a2dcc1b8053dbbbc12ef <58bd38cbc961fd799842b7be8c5222310f04b908; version=168a8f58059a22feb9e9a2dcc1b8053dbbbc12ef <88cd232146207ff1d41dededed5e77c0d4438113; version=168a8f58059a22feb9e9a2dcc1b8053dbbbc12ef <bdc28a8fb43cc476e33b11519235adb816ce00e8; version=168a8f58059a22feb9e9a2dcc1b8053dbbbc12ef <c348b0f8d035fc4bdc040796889beec7218bd1b8; version=168a8f58059a22feb9e9a2dcc1b8053dbbbc12ef <d05c2fdf8e10528bb6751bd95243e862d5402a9b; version=168a8f58059a22feb9e9a2dcc1b8053dbbbc12ef <d8e1bc6029acac796293310aacef7b7336f35b6a; version=3.7

Published CVSS scores

5.5UbuntuCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
5.5SUSECVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
5.5NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
5.5Amazon LinuxCVSS:3.1/AV:L/AC:L/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

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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

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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