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Review reviewHigh

CVE-2026-63942

Linux

In the Linux kernel, the following vulnerability has been resolved: parport: Fix race between port and client registration The parport subsystem registers port devices before they are fully initialised, resulting in a race condition where client drivers such as lp can attach to ports that are not completely initialised or even being torn down. When the port and client drivers are built as modules and loaded around the same time during boot, this occasionally results in a crash. I was able to make this happen reliably in a VM with a PC-style parallel port by patching parport_pc to fail probi...

CVSS
7.8
EPSS
-
- percentile
CISA KEV
Not listed
Published
2026.07.20
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability-
Technical severityCVSS 7.8

Vulnerability overview

In the Linux kernel, the following vulnerability has been resolved: parport: Fix race between port and client registration The parport subsystem registers port devices before they are fully initialised, resulting in a race condition where client drivers such as lp can attach to ports that are not completely initialised or even being torn down. When the port and client drivers are built as modules and loaded around the same time during boot, this occasionally results in a crash. I was able to make this happen reliably in a VM with a PC-style parallel port by patching parport_pc to fail probi...

Affected product and versions

Product
Linux
Affected versions
>= 6fa45a22689722dac9f0e90c0931d4b34b334ede < f3378b0d7bd4605de89b083b2900788157a181cc, >= 6fa45a22689722dac9f0e90c0931d4b34b334ede < 290f515c5e3b3900bc2fe24f179999fd08d23bfa, >= 6fa45a22689722dac9f0e90c0931d4b34b334ede < d16548be2ea5058227d79799e81dab61c9bca8ec, >= 6fa45a22689722dac9f0e90c0931d4b34b334ede < 15b1723c1472e802f9f7e69ae4e64f7dbf588848, >= 6fa45a22689722dac9f0e90c0931d4b34b334ede < 51026cff1f4f3b762a0b5a07c727bd59cef45320, >= 6fa45a22689722dac9f0e90c0931d4b34b334ede < 74d6aae1df45d3414178986be743f946988fddf6, >= 6fa45a22689722dac9f0e90c0931d4b34b334ede < a1e81b58da0179531bedf0b9f2811f5f992d5c4b, >= 6fa45a22689722dac9f0e90c0931d4b34b334ede < ef15ccbb3e8640a723c42ad90eaf81d66ae02017, >= 4.2
Fixed versions
No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that Linux and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE
Not available
CVE-2026-63942 — Linux | SECUFOCUS NOW