CVE-2026-98752 - Vulnerability Details

- tty: port: fix tty_port_tty_vhangup() race

Description

In the Linux kernel, the following vulnerability has been resolved:

tty: port: fix tty_port_tty_vhangup() race

Drivers rely on tty_port_tty_vhangup() to synchronously hang up their
ports before tearing down resources as part of deregistration (e.g. on
physical disconnect).

If tty_port_tty_vhangup() races with another hangup it may however
return before the port has been shut down. This is in turn can lead to
use-after-free and NULL-pointer dereferences in racing ioctls (including
a synchronous hangup) and in processing of racing asynchronous hangups
(carrier loss).

Add the missing serialisation to tty_port_tty_vhangup() and
tty_port_hangup() so that the former does not return until the port has
been shut down also when there is a racing hangup.

Note that serial core does not use tty_port_hangup(), but it already
holds the port mutex when clearing port->tty and shutting down the port
in uart_hangup().

Published: 2026-10-18

Score: 4.7 Medium

EPSS: < 1% Very Low

KEV: No

Impact:

Action:

Analysis

Impact

A race condition exists in the Linux kernel tty subsystem where the function tty_port_tty_vhangup() can complete before the port has fully shut down. This race allows concurrent hangup operations to result in use‑after‑free and NULL‑pointer dereference vulnerabilities, resulting in kernel memory corruption that can cause crashes, data corruption, or denial of service.

Affected Systems

All versions of the Linux kernel that contain the tty port management code and have not applied the commits referenced in the advisory are affected. This includes the default kernels shipped by distributions and any derivative kernels that have not incorporated the patch.

Risk and Exploitability

The CVSS score of 4.7 indicates moderate severity, and an EPSS score of less than 1% implies a very low likelihood of exploitation under typical circumstances. The vulnerability is not listed in the CISA KEV catalog. Based on the description, it is inferred that the race can be triggered by concurrent ioctl calls to a tty device. A successful exploitation could result in a kernel crash or denial of service.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

Linux

unaffected

Version	Status	Constraints
`7ca0ff9ab3218ec443a7a9ad247e4650373ed41e`	affected	< a78910f6d78cc1415cbc9b4fb621c3f4f6945be2
`7ca0ff9ab3218ec443a7a9ad247e4650373ed41e`	affected	< 2e16ae1464a4f435425c6f6ff1e293db850a624c
`7ca0ff9ab3218ec443a7a9ad247e4650373ed41e`	affected	< a776d603d1e1bba2837295817b0a39394707b10d
`7ca0ff9ab3218ec443a7a9ad247e4650373ed41e`	affected	< ce220b4cdf62f73db0c1940f968eb33b9899fdd0
`7ca0ff9ab3218ec443a7a9ad247e4650373ed41e`	affected	< 6d1a984afc3ca477dab3e51ec806671d443ad524
`7ca0ff9ab3218ec443a7a9ad247e4650373ed41e`	affected	< 6b7be3b9b857947e9c1338d4919d4ebd3b75e907
`7ca0ff9ab3218ec443a7a9ad247e4650373ed41e`	affected	< 017b18addbe8dcace1a569a00d40ed1ba1e03f4c
`7ca0ff9ab3218ec443a7a9ad247e4650373ed41e`	affected	< b48820de8c1a596c5b99775524dfce73c6576c5d
`4260dc792fabfd20c8644fa9414b2ae48372365f`	affected	—
`2.6.31.2`	affected	< 2.6.32

Linux

affected

Version	Status	Constraints
`2.6.32`	affected	—
`0`	unaffected	< 2.6.32
`5.10.273`	unaffected	≤ 5.10.*
`5.15.224`	unaffected	≤ 5.15.*
`6.1.191`	unaffected	≤ 6.1.*
`6.6.160`	unaffected	≤ 6.6.*
`6.12.113`	unaffected	≤ 6.12.*
`6.18.56`	unaffected	≤ 6.18.*
`7.2.10`	unaffected	≤ 7.2.*
`7.3`	unaffected	≤ *

No data.

Vendor Product Confidence Versions

Linux

Linux Kernel

99%

Version	Status	Scheme	Platform
`[7ca0ff9ab3218ec443a7a9ad247e4650373ed41e,6d1a984afc3ca477dab3e51ec806671d443ad524)`	affected	code_commit	—
`[7ca0ff9ab3218ec443a7a9ad247e4650373ed41e,6b7be3b9b857947e9c1338d4919d4ebd3b75e907)`	affected	code_commit	—
`[7ca0ff9ab3218ec443a7a9ad247e4650373ed41e,017b18addbe8dcace1a569a00d40ed1ba1e03f4c)`	affected	code_commit	—
`[7ca0ff9ab3218ec443a7a9ad247e4650373ed41e,b48820de8c1a596c5b99775524dfce73c6576c5d)`	affected	code_commit	—
`4260dc792fabfd20c8644fa9414b2ae48372365f`	affected	code_commit	—
`[2.6.31.2,2.6.32)`	affected	generic	—

Linux

Linux Kernel

99%

Version	Status	Scheme	Platform
`2.6.32`	affected	semver	—
`[0,2.6.32)`	unaffected	generic	—
`[6.12.113,6.13.0)`	unaffected	semver	—
`[6.18.56,6.19.0)`	unaffected	semver	—
`[7.2.10,7.3.0)`	unaffected	semver	—
`[7.3,*]`	unaffected	generic	—

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Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

Apply a kernel update that includes the commits fixing tty_port_tty_vhangup() and tty_port_hangup() (referenced in the advisory).
If a kernel upgrade is not possible, unload or disable tty and serial modules that are not required or restrict their use by setting udev rules or module options to minimize exposure.
Enforce strict access controls on tty devices, such as SELinux, AppArmor, or systemd‑udev rules, to allow only trusted users or processes to issue ioctl commands on serial or tty devices.

Generated by OpenCVE AI on October 23, 2026 at 23:25 UTC.

Tracking

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Advisories

Source	ID	Title
Debian DLA	DLA-4850-1	linux-6.12 security update

No CVSS v4.0

Attack Vector Local

Attack Complexity High

Privileges Required Low

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

The EPSS score is 0.00176.

Key SSVC decision points have not yet been added.

References

Link	Providers
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98752.mbox
https://git.kernel.org/stable/c/017b18addbe8dcace1a569a00d40ed1ba1e03f4c
https://git.kernel.org/stable/c/2e16ae1464a4f435425c6f6ff1e293db850a624c
https://git.kernel.org/stable/c/6b7be3b9b857947e9c1338d4919d4ebd3b75e907
https://git.kernel.org/stable/c/6d1a984afc3ca477dab3e51ec806671d443ad524
https://git.kernel.org/stable/c/a776d603d1e1bba2837295817b0a39394707b10d
https://git.kernel.org/stable/c/a78910f6d78cc1415cbc9b4fb621c3f4f6945be2
https://git.kernel.org/stable/c/b48820de8c1a596c5b99775524dfce73c6576c5d
https://git.kernel.org/stable/c/ce220b4cdf62f73db0c1940f968eb33b9899fdd0
https://nvd.nist.gov/vuln/detail/CVE-2026-98752
https://www.cve.org/CVERecord?id=CVE-2026-98752

History

Fri, 30 Oct 2026 12:45:00 +0000

Type	Values Removed	Values Added
References		https://git.kernel.org/stable/c/2e16ae1464a4f435425c6f6ff1e293db850a624c https://git.kernel.org/stable/c/a776d603d1e1bba2837295817b0a39394707b10d https://git.kernel.org/stable/c/a78910f6d78cc1415cbc9b4fb621c3f4f6945be2

Fri, 23 Oct 2026 20:00:00 +0000

Type	Values Removed	Values Added
Weaknesses	CWE-362 CWE-416 CWE-476

Fri, 23 Oct 2026 12:30:00 +0000

Type	Values Removed	Values Added
Weaknesses		CWE-366
References		https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98752.mbox https://nvd.nist.gov/vuln/detail/CVE-2026-98752 https://www.cve.org/CVERecord?id=CVE-2026-98752
Metrics	threat_severity `None`	cvssV3_1 `{'score': 4.7, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H'}` threat_severity `Moderate`

Wed, 21 Oct 2026 13:15:00 +0000

Type	Values Removed	Values Added
References		https://git.kernel.org/stable/c/ce220b4cdf62f73db0c1940f968eb33b9899fdd0

Sun, 18 Oct 2026 22:30:00 +0000

Type	Values Removed	Values Added
Weaknesses		CWE-362 CWE-416 CWE-476

Sun, 18 Oct 2026 16:00:00 +0000

Type	Values Removed	Values Added
Description		In the Linux kernel, the following vulnerability has been resolved: tty: port: fix tty_port_tty_vhangup() race Drivers rely on tty_port_tty_vhangup() to synchronously hang up their ports before tearing down resources as part of deregistration (e.g. on physical disconnect). If tty_port_tty_vhangup() races with another hangup it may however return before the port has been shut down. This is in turn can lead to use-after-free and NULL-pointer dereferences in racing ioctls (including a synchronous hangup) and in processing of racing asynchronous hangups (carrier loss). Add the missing serialisation to tty_port_tty_vhangup() and tty_port_hangup() so that the former does not return until the port has been shut down also when there is a racing hangup. Note that serial core does not use tty_port_hangup(), but it already holds the port mutex when clearing port->tty and shutting down the port in uart_hangup().
Title		tty: port: fix tty_port_tty_vhangup() race
First Time appeared		Linux Linux linux Kernel
CPEs		cpe:2.3:o:linux:linux_kernel::::::::
Vendors & Products		Linux Linux linux Kernel
References		https://git.kernel.org/stable/c/017b18addbe8dcace1a569a00d40ed1ba1e03f4c https://git.kernel.org/stable/c/6b7be3b9b857947e9c1338d4919d4ebd3b75e907 https://git.kernel.org/stable/c/6d1a984afc3ca477dab3e51ec806671d443ad524 https://git.kernel.org/stable/c/b48820de8c1a596c5b99775524dfce73c6576c5d

Subscriptions

Linux Linux Kernel

MITRE

Status: PUBLISHED

Assigner: Linux

Published: 2026-10-18T15:47:36.877Z

Updated: 2026-10-30T12:39:22.635Z

Reserved: 2026-09-25T10:25:14.368Z

Link: CVE-2026-98752

Vulnrichment

No data.

NVD

Status : Received

Published: 2026-10-18T16:17:28.993

Modified: 2026-10-30T13:21:24.107

Link: CVE-2026-98752

Redhat

Severity : Moderate

Publid Date: 2026-10-18T00:00:00Z

Links: CVE-2026-98752 - Bugzilla

OpenCVE Enrichment

Updated: 2026-10-23T23:30:17Z

Weaknesses

CWE-366
Race Condition within a Thread

Impact

Affected Systems

Risk and Exploitability

Tracking

Attack Vector Local

Attack Complexity High

Privileges Required Low

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

Subscriptions

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