CVE-2026-63942Public exploit

Kernel crash via premature parport device registration

Published Jul 19, 2026 · Updated Jul 19, 2026

Race condition in the Linux Kernel parport subsystem allows local users to crash the kernel by racing module registration. The subsystem exposes a port device before initialization and announcement finish, so lp or ppdev can attach to partial or tearing-down state. Triggering requires local CAP_SYS_MODULE access and concurrent loading or unloading of parport client and port drivers; the grounded result is an oops or panic.

CVSS severity7.8
High
EPSS probability0.16%
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

Race condition in the Linux Kernel parport subsystem allows local users to crash the kernel by racing module registration. The subsystem exposes a port device before initialization and announcement finish, so lp or ppdev can attach to partial or tearing-down state. Triggering requires local CAP_SYS_MODULE access and concurrent loading or unloading of parport client and port drivers; the grounded result is an oops or panic.

The record

CVE
CVE-2026-63942
Published
Jul 19, 2026
Updated
Jul 19, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-367, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 19, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 19, 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=4.2
  2. Affected versionversion=6fa45a22689722dac9f0e90c0931d4b34b334ede <15b1723c1472e802f9f7e69ae4e64f7dbf588848
  3. Affected versionversion=6fa45a22689722dac9f0e90c0931d4b34b334ede <290f515c5e3b3900bc2fe24f179999fd08d23bfa
  4. Affected versionversion=6fa45a22689722dac9f0e90c0931d4b34b334ede <51026cff1f4f3b762a0b5a07c727bd59cef45320
  5. Affected versionversion=6fa45a22689722dac9f0e90c0931d4b34b334ede <74d6aae1df45d3414178986be743f946988fddf6
  6. Affected versionversion=6fa45a22689722dac9f0e90c0931d4b34b334ede <a1e81b58da0179531bedf0b9f2811f5f992d5c4b
  7. Affected versionversion=6fa45a22689722dac9f0e90c0931d4b34b334ede <d16548be2ea5058227d79799e81dab61c9bca8ec
  8. Affected versionversion=6fa45a22689722dac9f0e90c0931d4b34b334ede <ef15ccbb3e8640a723c42ad90eaf81d66ae02017
  9. Affected versionversion=6fa45a22689722dac9f0e90c0931d4b34b334ede <f3378b0d7bd4605de89b083b2900788157a181cc

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=4.2; version=6fa45a22689722dac9f0e90c0931d4b34b334ede <15b1723c1472e802f9f7e69ae4e64f7dbf588848; version=6fa45a22689722dac9f0e90c0931d4b34b334ede <290f515c5e3b3900bc2fe24f179999fd08d23bfa; version=6fa45a22689722dac9f0e90c0931d4b34b334ede <51026cff1f4f3b762a0b5a07c727bd59cef45320; version=6fa45a22689722dac9f0e90c0931d4b34b334ede <74d6aae1df45d3414178986be743f946988fddf6; version=6fa45a22689722dac9f0e90c0931d4b34b334ede <a1e81b58da0179531bedf0b9f2811f5f992d5c4b; version=6fa45a22689722dac9f0e90c0931d4b34b334ede <d16548be2ea5058227d79799e81dab61c9bca8ec; version=6fa45a22689722dac9f0e90c0931d4b34b334ede <ef15ccbb3e8640a723c42ad90eaf81d66ae02017; version=6fa45a22689722dac9f0e90c0931d4b34b334ede <f3378b0d7bd4605de89b083b2900788157a181cc

Published CVSS scores

5.5Red HatCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
7.8kernel.orgCVSS:3.1/AV:L/AC:L/PR:L/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)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-367Time-of-check Time-of-use (TOCTOU) Race Condition
T1499.004Application or System Exploitation

Public exploit references

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