CVE-2026-63942 | Vulnerability Intelligence

Stored catalog record

Source record retrieved 2026-10-28T10:25:50.542756+00:00. Scheduled imports handle updates; this page does not assert that the provider was queried just now.

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 probing: > --- a/drivers/parport/parport_pc.c > +++ b/drivers/parport/parport_pc.c > @@ -2069,7 +2069,7 @@ static struct parport *__parport_pc_probe_port(unsigned long int base, > if (!p) > goto out3; > > - base_res = request_region(base, 3, p->name); > + base_res = NULL; > if (!base_res) > goto out4; > and then running: while true; do modprobe lp & modprobe parport_pc wait rmmod lp parport_pc done for a few seconds. In the long term I think port registration should be changed to put the call to device_add() inside parport_announce_port(), but since the latter currently cannot fail this will require changing all port drivers. For now, add a flag to indicate whether a port has been "announced" and only try to attach client drivers to ports when the flag is set.

Patch review priority

Assess exposure and vendor guidance

No higher-priority signal is available in the current stored evidence.

FIRST EPSS: 0.13% · percentile 2.7 · score date 2026-10-27.

EPSS estimates probability of exploitation in the next 30 days. It does not measure your exposure or prove exploitation. The elevated threshold is 10%; CISA KEV takes precedence. About FIRST EPSS ↗

Severity and scoring

CVSS score: 7.8 · HIGH
CVSS version: 3.1
CVSS vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weaknesses: CWE-362

CVSS measures technical severity; it does not establish whether this vulnerability is being exploited in your environment.

Known exploitation and remediation

Not listed in the CISA catalog retrieved for this record. This does not establish that exploitation has not occurred.

Verify affected versions and patch availability in the vendor advisory before making changes.

Affected products and versions

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
From (inclusive): 4.2
Before (exclusive): 5.10.259
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
From (inclusive): 5.11
Before (exclusive): 5.15.210
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
From (inclusive): 5.16
Before (exclusive): 6.1.176
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
From (inclusive): 6.2
Before (exclusive): 6.6.143
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
From (inclusive): 6.7
Before (exclusive): 6.12.93
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
From (inclusive): 6.13
Before (exclusive): 6.18.35
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
From (inclusive): 6.19
Before (exclusive): 7.0.12
cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.1:rc5:*:*:*:*:*:*

These are NVD CPE applicability entries. Some products depend on configuration conditions; consult the official record to confirm applicability.

Advisories and references

Explore official sources

Read the official NVD record ↗

Explore the CISA catalog ↗

Back to CVE intelligence