CVE-2026-43055Network attack vector

Remote write rejection via uninitialized stream selector

Published May 1, 2026 · Updated May 1, 2026

Availability flaw in Linux Kernel allows remote attackers to reject writes to exported FILEIO LUNs through network SCSI commands. target_core_file allocates aio_cmd without zeroing iocb.ki_write_stream, so fd_execute_rw_aio reads stale data and rejects writes when the bogus selector exceeds the block-device maximum. Exposure requires an affected kernel with asynchronous FILEIO enabled and an exported SCSI target; repeated commands interrupt legitimate storage writes.

CVSS severity7.5
High
EPSS probability0.36%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Availability flaw in Linux Kernel allows remote attackers to reject writes to exported FILEIO LUNs through network SCSI commands. target_core_file allocates aio_cmd without zeroing iocb.ki_write_stream, so fd_execute_rw_aio reads stale data and rejects writes when the bogus selector exceeds the block-device maximum. Exposure requires an affected kernel with asynchronous FILEIO enabled and an exported SCSI target; repeated commands interrupt legitimate storage writes.

The record

CVE
CVE-2026-43055
Published
May 1, 2026
Updated
May 1, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 1, 2026CVE publishedPublication date reported by the CVE source.
  2. May 1, 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=6.16
  2. Affected versionversion=732f25a2895a8c1c54fb56544f0b1e23770ef4d7 <01f784fc9d0ab2a6dac45ee443620e517cb2a19b
  3. Affected versionversion=732f25a2895a8c1c54fb56544f0b1e23770ef4d7 <4eaff1728d0e69b95933412241bbccf4f797dba8
  4. Affected versionversion=732f25a2895a8c1c54fb56544f0b1e23770ef4d7 <ce54802fe6bb78eb0feffc66fed6a45d41ffc3ab

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=6.16; version=732f25a2895a8c1c54fb56544f0b1e23770ef4d7 <01f784fc9d0ab2a6dac45ee443620e517cb2a19b; version=732f25a2895a8c1c54fb56544f0b1e23770ef4d7 <4eaff1728d0e69b95933412241bbccf4f797dba8; version=732f25a2895a8c1c54fb56544f0b1e23770ef4d7 <ce54802fe6bb78eb0feffc66fed6a45d41ffc3ab

Published CVSS scores

7.5kernel.orgCVSS:3.1/AV:N/AC:L/PR:N/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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

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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