CVE-2026-63899 - Vulnerability Details

- USB: serial: mxuport: fix memory corruption with small endpoint

Description

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

USB: serial: mxuport: fix memory corruption with small endpoint

Make sure that the bulk-out endpoint max packet size is at least eight
bytes to avoid user-controlled slab corruption should a malicious device
report a smaller size.

Published: 2026-07-19

Score: 7.0 High

EPSS: < 1% Very Low

KEV: No

Impact:

Action:

Analysis

Analysis and contextual insights are available on OpenCVE Cloud.

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
`ee467a1f2066d2bfa293f7c2c7f1ff7000b0a39e`	affected	< 086b858b5f5125bc9d967ea2bd825f83d9f8f29d
`ee467a1f2066d2bfa293f7c2c7f1ff7000b0a39e`	affected	< 2f3661eb2446e1ef593da45e01a3b21a906768ec
`ee467a1f2066d2bfa293f7c2c7f1ff7000b0a39e`	affected	< ccbec56f2f9af008f1574335cc6a668f16603e47
`ee467a1f2066d2bfa293f7c2c7f1ff7000b0a39e`	affected	< be3a1ed4ae51fa8dde57383277d336ce834f2cd9
`ee467a1f2066d2bfa293f7c2c7f1ff7000b0a39e`	affected	< e906545641d34fb1a09a65b4b5cfdff40eb09681
`ee467a1f2066d2bfa293f7c2c7f1ff7000b0a39e`	affected	< 6c0cf56f00f280d72180bb6ce79741bc787a6269
`ee467a1f2066d2bfa293f7c2c7f1ff7000b0a39e`	affected	< b40166b4ef96067620a0f248e74ad9658c8f680c
`ee467a1f2066d2bfa293f7c2c7f1ff7000b0a39e`	affected	< 4085f0dbb1ce2251c9a5938d693de6593f0ab2bd

Linux

affected

Version	Status	Constraints
`3.14`	affected	—
`0`	unaffected	< 3.14
`5.10.259`	unaffected	≤ 5.10.*
`5.15.210`	unaffected	≤ 5.15.*
`6.1.176`	unaffected	≤ 6.1.*
`6.6.143`	unaffected	≤ 6.6.*
`6.12.93`	unaffected	≤ 6.12.*
`6.18.35`	unaffected	≤ 6.18.*
`7.0.12`	unaffected	≤ 7.0.*
`7.1`	unaffected	≤ *

No data.

Vendor Product Confidence Versions

Linux

Linux Kernel

99%

Version	Status	Scheme	Platform
`[ee467a1f2066d2bfa293f7c2c7f1ff7000b0a39e,086b858b5f5125bc9d967ea2bd825f83d9f8f29d)`	affected	code_commit	—
`[ee467a1f2066d2bfa293f7c2c7f1ff7000b0a39e,2f3661eb2446e1ef593da45e01a3b21a906768ec)`	affected	code_commit	—
`[ee467a1f2066d2bfa293f7c2c7f1ff7000b0a39e,ccbec56f2f9af008f1574335cc6a668f16603e47)`	affected	code_commit	—
`[ee467a1f2066d2bfa293f7c2c7f1ff7000b0a39e,be3a1ed4ae51fa8dde57383277d336ce834f2cd9)`	affected	code_commit	—
`[ee467a1f2066d2bfa293f7c2c7f1ff7000b0a39e,e906545641d34fb1a09a65b4b5cfdff40eb09681)`	affected	code_commit	—
`[ee467a1f2066d2bfa293f7c2c7f1ff7000b0a39e,6c0cf56f00f280d72180bb6ce79741bc787a6269)`	affected	code_commit	—
`[ee467a1f2066d2bfa293f7c2c7f1ff7000b0a39e,b40166b4ef96067620a0f248e74ad9658c8f680c)`	affected	code_commit	—
`[ee467a1f2066d2bfa293f7c2c7f1ff7000b0a39e,4085f0dbb1ce2251c9a5938d693de6593f0ab2bd)`	affected	code_commit	—

Linux

Linux Kernel

99%

Version	Status	Scheme	Platform
`3.14`	affected	generic	—
`[0,3.14)`	unaffected	generic	—
`[5.10.259,5.11.0)`	unaffected	semver	—
`[5.15.210,5.16.0)`	unaffected	semver	—
`[6.1.176,6.2.0)`	unaffected	semver	—
`[6.6.143,6.7.0)`	unaffected	semver	—
`[6.12.93,6.13.0)`	unaffected	semver	—
`[6.18.35,6.19.0)`	unaffected	semver	—
`[7.0.12,7.1.0)`	unaffected	semver	—
`[7.1,*]`	unaffected	generic	—

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Remediation

No vendor fix or workaround currently provided.

Additional remediation guidance may be available on OpenCVE Cloud.

Tracking

Sign in to view the affected projects.

Advisories

Source	ID	Title
Ubuntu USN	USN-8593-1	Linux kernel vulnerabilities
Ubuntu USN	USN-8603-1	Linux kernel (Azure) vulnerabilities
Ubuntu USN	USN-8618-1	Linux kernel vulnerabilities

No CVSS v4.0

Attack Vector Local

Attack Complexity High

Privileges Required Low

Scope Unchanged

Confidentiality Impact High

Integrity Impact High

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 0.00211.

Key SSVC decision points have not yet been added.

References

Link	Providers
https://git.kernel.org/stable/c/086b858b5f5125bc9d967ea2bd825f83d9f8f29d
https://git.kernel.org/stable/c/2f3661eb2446e1ef593da45e01a3b21a906768ec
https://git.kernel.org/stable/c/4085f0dbb1ce2251c9a5938d693de6593f0ab2bd
https://git.kernel.org/stable/c/6c0cf56f00f280d72180bb6ce79741bc787a6269
https://git.kernel.org/stable/c/b40166b4ef96067620a0f248e74ad9658c8f680c
https://git.kernel.org/stable/c/be3a1ed4ae51fa8dde57383277d336ce834f2cd9
https://git.kernel.org/stable/c/ccbec56f2f9af008f1574335cc6a668f16603e47
https://git.kernel.org/stable/c/e906545641d34fb1a09a65b4b5cfdff40eb09681
https://lore.kernel.org/linux-cve-announce/2026071943-CVE-2026-63899-cd10@gregkh/T
https://nvd.nist.gov/vuln/detail/CVE-2026-63899
https://www.cve.org/CVERecord?id=CVE-2026-63899

History

Wed, 22 Jul 2026 00:15:00 +0000

Type	Values Removed	Values Added
Weaknesses		CWE-120
References		https://lore.kernel.org/linux-cve-announce/2026071943-CVE-2026-63899-cd10@gregkh/T https://nvd.nist.gov/vuln/detail/CVE-2026-63899 https://www.cve.org/CVERecord?id=CVE-2026-63899
Metrics	threat_severity `None`	cvssV3_1 `{'score': 7.0, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'}` threat_severity `Important`

Sun, 19 Jul 2026 15:30:00 +0000

Type	Values Removed	Values Added
Description		In the Linux kernel, the following vulnerability has been resolved: USB: serial: mxuport: fix memory corruption with small endpoint Make sure that the bulk-out endpoint max packet size is at least eight bytes to avoid user-controlled slab corruption should a malicious device report a smaller size.
Title		USB: serial: mxuport: fix memory corruption with small endpoint
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/086b858b5f5125bc9d967ea2bd825f83d9f8f29d https://git.kernel.org/stable/c/2f3661eb2446e1ef593da45e01a3b21a906768ec https://git.kernel.org/stable/c/4085f0dbb1ce2251c9a5938d693de6593f0ab2bd https://git.kernel.org/stable/c/6c0cf56f00f280d72180bb6ce79741bc787a6269 https://git.kernel.org/stable/c/b40166b4ef96067620a0f248e74ad9658c8f680c https://git.kernel.org/stable/c/be3a1ed4ae51fa8dde57383277d336ce834f2cd9 https://git.kernel.org/stable/c/ccbec56f2f9af008f1574335cc6a668f16603e47 https://git.kernel.org/stable/c/e906545641d34fb1a09a65b4b5cfdff40eb09681

Subscriptions

Linux Linux Kernel

MITRE

Status: PUBLISHED

Assigner: Linux

Published: 2026-07-19T14:55:08.116Z

Updated: 2026-07-19T14:55:08.116Z

Reserved: 2026-07-19T07:54:57.019Z

Link: CVE-2026-63899

Vulnrichment

No data.

NVD

No data.

Redhat

Severity : Important

Publid Date: 2026-07-19T00:00:00Z

Links: CVE-2026-63899 - Bugzilla

OpenCVE Enrichment

Updated: 2026-07-27T20:30:09Z

Weaknesses

CWE-120
Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')

Tracking

Attack Vector Local

Attack Complexity High

Privileges Required Low

Scope Unchanged

Confidentiality Impact High

Integrity Impact High

Availability Impact High

User Interaction None

Subscriptions

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