CVE-2026-43087

Kernel crash via unregistered nested interrupt handler

Published May 6, 2026 · Updated May 6, 2026

Denial of service in the Linux Kernel 6.19 mcp23s08 pinctrl driver allows local users to crash the kernel during device probe. The probe path reads an enabled MCP_GPINTEN register and dispatches a pin interrupt before its nested handler exists, causing an invalid kernel memory access. The trigger requires an MCP23S08-compatible chip whose interrupt-on-change state remains enabled when driver probing begins.

CVSS severity5.5
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

Denial of service in the Linux Kernel 6.19 mcp23s08 pinctrl driver allows local users to crash the kernel during device probe. The probe path reads an enabled MCP_GPINTEN register and dispatches a pin interrupt before its nested handler exists, causing an invalid kernel memory access. The trigger requires an MCP23S08-compatible chip whose interrupt-on-change state remains enabled when driver probing begins.

The record

CVE
CVE-2026-43087
Published
May 6, 2026
Updated
May 6, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1529
Attack vector
local
Privileges
authenticated

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=6.19
  2. Affected versionversion=f9f4fda15e720686f1b2b436591ab11255e4e85e <db5b8cecbdf479ad13156af750377e5b43853fab
  3. Affected versionversion=f9f4fda15e720686f1b2b436591ab11255e4e85e <f8c3258541a0680a4ebc08b05b2bc5fdad3288a9

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=6.19; version=f9f4fda15e720686f1b2b436591ab11255e4e85e <db5b8cecbdf479ad13156af750377e5b43853fab; version=f9f4fda15e720686f1b2b436591ab11255e4e85e <f8c3258541a0680a4ebc08b05b2bc5fdad3288a9

Published CVSS scores

5.5NVDCVSS: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.

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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)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1529System Shutdown/Reboot

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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