VulnerabilityPublished 27 May 2026Updated 30 Oct 2026

CVE-2026-45855: Linux kernel · ata: libata-scsi: avoid Non-NCQ command starvation

Affects Linux kernelSource CVE Database V5

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Not known to be exploited · fixed in ce22aaed011206fed9cbd8c9c2d44718607f31ee : update Linux kernel when convenient.

Data as of 30 Oct 2026, 12:48 UTC

Severity

Medium

Rated Medium by Threat Radar's AI analysis · No CVSS score from NVD or the CNA

Thin evidence

One scorer or none

Patch: Available – fixed in ce22aaed011206fed9cbd8c9c2d44718607f31ee, c475bfce918dc413c4d59b97710b94b1c955ea5f, 888cd7e40adb2ef4af1b4d3b6e2e83ad409ae8c2 +2

Exploitation evidence

Disclosed: evidence found.
CVE published 27 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ bdb01301f3ea51a59eff252b06643fc1fe843e57, < ce22aaed011206fed9cbd8c9c2d44718607f31ee	Fixed in ce22aaed011206fed9cbd8c9c2d44718607f31ee
LinuxLinux	Affected ≥ bdb01301f3ea51a59eff252b06643fc1fe843e57, < c475bfce918dc413c4d59b97710b94b1c955ea5f	Fixed in c475bfce918dc413c4d59b97710b94b1c955ea5f
LinuxLinux	Affected ≥ bdb01301f3ea51a59eff252b06643fc1fe843e57, < 888cd7e40adb2ef4af1b4d3b6e2e83ad409ae8c2	Fixed in 888cd7e40adb2ef4af1b4d3b6e2e83ad409ae8c2
LinuxLinux	Affected ≥ bdb01301f3ea51a59eff252b06643fc1fe843e57, < 5d61a38a60e62750526d94663b69b7ac5c7f07a5	Fixed in 5d61a38a60e62750526d94663b69b7ac5c7f07a5
LinuxLinux	Affected ≥ bdb01301f3ea51a59eff252b06643fc1fe843e57, < 0ea84089dbf62a92dc7889c79e6b18fc89260808	Fixed in 0ea84089dbf62a92dc7889c79e6b18fc89260808
LinuxLinux	Affected =5.10	Fixed in–

AI-suggested

A fix is available and has been integrated into the Linux kernel. Systems running affected versions should update to a fixed kernel version containing the patches identified by the provided commit hashes. No additional mitigation is required once the patch is applied.

Description

CVE-2026-45855 is a vulnerability in the Linux kernel's libata-scsi subsystem that can cause starvation of non-NCQ commands when multiple submission queues are used. Non-NCQ commands may be repeatedly deferred if the device is under constant NCQ command load, leading to long delays or complete starvation. The issue is addressed by implementing a forward progress guarantee for non-NCQ commands, ensuring they are eventually executed even under heavy NCQ traffic.

Impact

The impact is primarily performance degradation and potential denial of service for non-NCQ commands, which may experience very long delays or complete starvation under heavy NCQ command load. This can affect system stability and responsiveness when non-NCQ commands are critical. There is no indication of code execution or data corruption from this vulnerability.

Summary

This vulnerability affects the Linux kernel's ATA SCSI layer where non-NCQ commands can be starved due to repeated deferral when multiple submission queues are active and the device is continuously processing NCQ commands. The problem arises because the block and SCSI layers do not differentiate between queueable (NCQ) and non-queueable (non-NCQ) commands, causing non-NCQ commands to be deferred indefinitely. The fix introduces a mechanism to hold and defer non-NCQ commands internally rather than requeueing them repeatedly, ensuring they are issued once in-flight NCQ commands complete. This approach prevents starvation and potential denial of service by managing command issuing and deferral carefully, including during error handling and device resets.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 30 Oct 2026, 12:48 UTC

Technical details

References

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