CVE-2026-43208Network attack vector

Kernel crash via mismatched RPS flow index

Published May 6, 2026 · Updated May 6, 2026

Out-of-bounds access in Linux Kernel allows remote attackers to crash systems by exercising receive packet steering. The set_rps_cpu() path reuses a flow_id calculated for one receive queue to index a different queue's flow table instead of recomputing rfs_slot() for that table. The failure occurs when flow steering crosses receive queues whose RPS tables differ in size or change, risking an invalid access and kernel crash.

CVSS severity9.8
Critical
EPSS probability0.48%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds access in Linux Kernel allows remote attackers to crash systems by exercising receive packet steering. The set_rps_cpu() path reuses a flow_id calculated for one receive queue to index a different queue's flow table instead of recomputing rfs_slot() for that table. The failure occurs when flow steering crosses receive queues whose RPS tables differ in size or change, risking an invalid access and kernel crash.

The record

CVE
CVE-2026-43208
Published
May 6, 2026
Updated
May 6, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-787, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 6, 2026CVE publishedPublication date reported by the CVE source.
  2. May 6, 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=48aa30443e52c9666d5cd5e67532e475f212337e <5455a232edea6b946b99449f15ca771a8874a5a6
  2. Affected versionversion=48aa30443e52c9666d5cd5e67532e475f212337e <8a8a9fac9efa6423fd74938b940cb7d731780718
  3. Affected versionversion=48aa30443e52c9666d5cd5e67532e475f212337e <ed712dc0d64dee5f0d05e4d8ca57711f8a9c850c
  4. Affected versionversion=6.18

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=48aa30443e52c9666d5cd5e67532e475f212337e <5455a232edea6b946b99449f15ca771a8874a5a6; version=48aa30443e52c9666d5cd5e67532e475f212337e <8a8a9fac9efa6423fd74938b940cb7d731780718; version=48aa30443e52c9666d5cd5e67532e475f212337e <ed712dc0d64dee5f0d05e4d8ca57711f8a9c850c; version=6.18

Published CVSS scores

9.8kernel.orgCVSS:3.1/AV:N/AC:L/PR:N/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.

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

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write
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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