CVE-2023-53188

CPU hang via stale Open vSwitch vport output

Published Sep 15, 2025 · Updated Sep 15, 2025

Race condition in the Linux kernel Open vSwitch module allows local users to hang a CPU during network namespace teardown. During vport removal, do_output can forward a packet to an unregistering device after real_num_tx_queues reaches zero, leaving skb_tx_hash in an infinite loop. Triggering the hang requires CAP_NET_ADMIN, a multi-queue Open vSwitch and veth setup, sustained parallel traffic, and concurrent namespace deletion.

CVSS severity4.7
Medium
EPSS probability0.11%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Race condition in the Linux kernel Open vSwitch module allows local users to hang a CPU during network namespace teardown. During vport removal, do_output can forward a packet to an unregistering device after real_num_tx_queues reaches zero, leaving skb_tx_hash in an infinite loop. Triggering the hang requires CAP_NET_ADMIN, a multi-queue Open vSwitch and veth setup, sustained parallel traffic, and concurrent namespace deletion.

The record

CVE
CVE-2023-53188
Published
Sep 15, 2025
Updated
Sep 15, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-821, T1499.004
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Sep 15, 2025CVE publishedPublication date reported by the CVE source.
  2. Sep 15, 2025Record 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=4.3
  2. Affected versionversion=7f8a436eaa2c3ddd8e1ff2fbca267e6275085536 <066b86787fa3d97b7aefb5ac0a99a22dad2d15f8
  3. Affected versionversion=7f8a436eaa2c3ddd8e1ff2fbca267e6275085536 <284be5db6c8d06d247ed056cfc448c4f79bbb16c
  4. Affected versionversion=7f8a436eaa2c3ddd8e1ff2fbca267e6275085536 <56252da41426f3d01957456f13caf46ce670ea29
  5. Affected versionversion=7f8a436eaa2c3ddd8e1ff2fbca267e6275085536 <5efcb301523baacd98a47553d4996e924923114d
  6. Affected versionversion=7f8a436eaa2c3ddd8e1ff2fbca267e6275085536 <644b3051b06ba465bc7401bfae9b14963cbc8c1c
  7. Affected versionversion=7f8a436eaa2c3ddd8e1ff2fbca267e6275085536 <9b0dd09c1ceb35950d2884848099fccc9ec9a123

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

The Linux Kernel Organization · Linuxversion=4.3; version=7f8a436eaa2c3ddd8e1ff2fbca267e6275085536 <066b86787fa3d97b7aefb5ac0a99a22dad2d15f8; version=7f8a436eaa2c3ddd8e1ff2fbca267e6275085536 <284be5db6c8d06d247ed056cfc448c4f79bbb16c; version=7f8a436eaa2c3ddd8e1ff2fbca267e6275085536 <56252da41426f3d01957456f13caf46ce670ea29; version=7f8a436eaa2c3ddd8e1ff2fbca267e6275085536 <5efcb301523baacd98a47553d4996e924923114d; version=7f8a436eaa2c3ddd8e1ff2fbca267e6275085536 <644b3051b06ba465bc7401bfae9b14963cbc8c1c; version=7f8a436eaa2c3ddd8e1ff2fbca267e6275085536 <9b0dd09c1ceb35950d2884848099fccc9ec9a123

Published CVSS scores

5.5Amazon LinuxCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
4.4Red HatCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
4.7NVDCVSS: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

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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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-821Incorrect Synchronization
T1499.004Endpoint 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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