CVE-2026-43475

Local guest lock-up via preemption-disabled ring-buffer locking

Published May 8, 2026 · Updated May 8, 2026

A scheduling flaw in the Linux Kernel storvsc driver allows local users to lock up PREEMPT_RT Hyper-V guests during storage I/O. In storvsc_queuecommand(), get_cpu() disables preemption before storvsc_do_io() reaches hv_ringbuffer_write(), whose spinlock becomes a sleepable rt-mutex under PREEMPT_RT. Any low-privilege local user able to generate storage I/O in such a guest can hang the operating system, without reported data disclosure or modification.

CVSS severity5.5
Medium
EPSS probability0.11%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

A scheduling flaw in the Linux Kernel storvsc driver allows local users to lock up PREEMPT_RT Hyper-V guests during storage I/O. In storvsc_queuecommand(), get_cpu() disables preemption before storvsc_do_io() reaches hv_ringbuffer_write(), whose spinlock becomes a sleepable rt-mutex under PREEMPT_RT. Any low-privilege local user able to generate storage I/O in such a guest can hang the operating system, without reported data disclosure or modification.

The record

CVE
CVE-2026-43475
Published
May 8, 2026
Updated
May 8, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 8, 2026CVE publishedPublication date reported by the CVE source.
  2. May 8, 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=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <57297736c08233987e5d29ce6584c6ca2a831b12
  2. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <91ab59f76d0866079420ebff1c7959fcd87a242e
  3. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <b82462af23e45e066dd56d2736ea70159a6ad647
  4. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <c2e73d8acd056347a70047e6be7cd98e0e811dfa
  5. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <c7984d196476adcbd51c0ce386d7e90277198d57
  6. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <cf00cb15f2515e38d3b7571bf6800b7c6ce70a84
  7. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <e7919a293f9b6101e38bde0d8613daea6c9955df
  8. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <f8db760f4f52a73a022a3d6c84c488ead952a9b5

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <57297736c08233987e5d29ce6584c6ca2a831b12; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <91ab59f76d0866079420ebff1c7959fcd87a242e; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <b82462af23e45e066dd56d2736ea70159a6ad647; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <c2e73d8acd056347a70047e6be7cd98e0e811dfa; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <c7984d196476adcbd51c0ce386d7e90277198d57; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <cf00cb15f2515e38d3b7571bf6800b7c6ce70a84; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <e7919a293f9b6101e38bde0d8613daea6c9955df; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <f8db760f4f52a73a022a3d6c84c488ead952a9b5

Published CVSS scores

5.5NIST NVDCVSS: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

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)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499.004Endpoint Denial of Service: Application 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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo