CVE-2026-64271

Input: touchwin - reset the packet index on every complete packet

Published Jul 25, 2026 CVSS 3.1 · 7.8 High EPSS < 1% KEV · Not listed

Description

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

Input: touchwin - reset the packet index on every complete packet

tw_interrupt() accumulates each non-zero serial byte into a fixed
three-byte buffer with a running index that is only reset once a full
packet has been received *and* the device's two Y bytes agree:

tw->data[tw->idx++] = data;
if (tw->idx == TW_LENGTH && tw->data[1] == tw->data[2]) {
...
tw->idx = 0;
}

The reset is gated on tw->data[1] == tw->data[2], a value the device
controls. A malicious, malfunctioning or counterfeit Touchwindow
peripheral can stream non-zero bytes whose 2nd and 3rd bytes differ: the
index reaches TW_LENGTH without the equality holding, is never reset, and
keeps growing, so tw->data[tw->idx++] walks off the end of the three-byte
array and the rest of the heap-allocated struct tw, one attacker-chosen
byte at a time -- an unbounded, device-driven heap out-of-bounds write.

Reset the index on every completed packet and report an event only when
the two Y bytes match, like the other serio touchscreen drivers do.

Affected Products

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
`11ea3173d5f2de71d037ef58ac43395795fed2bc`	affected	< ed9b66905407eb3d02df1aaeed82eb7a7f0eb508
`11ea3173d5f2de71d037ef58ac43395795fed2bc`	affected	< 044167cba2384bcd783547ad5e30ecd292b30919
`11ea3173d5f2de71d037ef58ac43395795fed2bc`	affected	< 6c9f29f128dd4057404838259af4c645318487e1
`11ea3173d5f2de71d037ef58ac43395795fed2bc`	affected	< 431ad239f2924dff337c3fccb9246597c1b63185
`11ea3173d5f2de71d037ef58ac43395795fed2bc`	affected	< 70e4248793762df9832fd4fc2fc6ac7924572c36
`11ea3173d5f2de71d037ef58ac43395795fed2bc`	affected	< 3e6f007b43e2fc6546e21fa74ee62c38984a6672
`11ea3173d5f2de71d037ef58ac43395795fed2bc`	affected	< a8d87184576c889759e3aab899799a482f1e1a5b
`11ea3173d5f2de71d037ef58ac43395795fed2bc`	affected	< 478cdd736f2ce3114f90e775d7358136d3977b94

Linux

affected

Version	Status	Constraints
`2.6.19`	affected	—
`0`	unaffected	< 2.6.19
`5.10.261`	unaffected	≤ 5.10.*
`5.15.212`	unaffected	≤ 5.15.*
`6.1.178`	unaffected	≤ 6.1.*
`6.6.145`	unaffected	≤ 6.6.*
`6.12.96`	unaffected	≤ 6.12.*
`6.18.39`	unaffected	≤ 6.18.*
`7.1.4`	unaffected	≤ 7.1.*
`7.2`	unaffected	≤ *

Configuration 1 [-]

OR	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::

No data.

Vendor Product Versions

Linux

Linux Kernel

Version	Status	Scheme	Platform
`[11ea3173d5f2de71d037ef58ac43395795fed2bc,ed9b66905407eb3d02df1aaeed82eb7a7f0eb508)`	affected	code_commit	—
`[11ea3173d5f2de71d037ef58ac43395795fed2bc,044167cba2384bcd783547ad5e30ecd292b30919)`	affected	code_commit	—
`[11ea3173d5f2de71d037ef58ac43395795fed2bc,3e6f007b43e2fc6546e21fa74ee62c38984a6672)`	affected	code_commit	—
`[11ea3173d5f2de71d037ef58ac43395795fed2bc,431ad239f2924dff337c3fccb9246597c1b63185)`	affected	code_commit	—
`[11ea3173d5f2de71d037ef58ac43395795fed2bc,70e4248793762df9832fd4fc2fc6ac7924572c36)`	affected	code_commit	—
`[11ea3173d5f2de71d037ef58ac43395795fed2bc,a8d87184576c889759e3aab899799a482f1e1a5b)`	affected	code_commit	—
`[11ea3173d5f2de71d037ef58ac43395795fed2bc,478cdd736f2ce3114f90e775d7358136d3977b94)`	affected	code_commit	—
`[11ea3173d5f2de71d037ef58ac43395795fed2bc,6c9f29f128dd4057404838259af4c645318487e1)`	affected	code_commit	—

Linux

Linux Kernel

Version	Status	Scheme	Platform
`2.6.19`	affected	semver	—
`[0,2.6.19)`	unaffected	semver	—
`[5.10.261,5.11.0)`	unaffected	semver	—
`[5.15.212,5.16.0)`	unaffected	semver	—
`[6.1.178,6.2.0)`	unaffected	semver	—
`[6.6.145,6.7.0)`	unaffected	semver	—
`[6.12.96,6.13.0)`	unaffected	semver	—
`[6.18.39,6.19.0)`	unaffected	semver	—
`[7.1.4,7.2.0)`	unaffected	semver	—
`[7.2-rc1,*]`	unaffected	generic	—

Remediation

No solution or workaround provided in the CVE record

Tracking

Advisories

Source	ID	Title
Debian DLA	DLA-4717-1	linux security update
Debian DLA	DLA-4720-1	linux security update
Debian DLA	DLA-4723-1	linux-6.1 security update
Debian DLA	DLA-4724-1	linux-6.12 new package
Ubuntu USN	USN-8726-1	Linux kernel vulnerabilities
Ubuntu USN	USN-8727-1	Linux kernel (OEM) vulnerabilities
Ubuntu USN	USN-8728-1	Linux kernel (GCP) vulnerabilities
Ubuntu USN	USN-8760-1	Linux kernel (NVIDIA) vulnerabilities
Ubuntu USN	USN-8726-2	Linux kernel (Raspberry Pi) vulnerabilities
Ubuntu USN	USN-8726-3	Linux kernel (IBM) vulnerabilities
Ubuntu USN	USN-8800-1	Linux kernel (NVIDIA BaseOS) vulnerabilities
Ubuntu USN	USN-8760-2	Linux kernel (NVIDIA) vulnerabilities
Ubuntu USN	USN-8726-4	Linux kernel vulnerabilities
Ubuntu USN	USN-8728-2	Linux kernel (Azure) vulnerabilities
Ubuntu USN	USN-8728-3	Linux kernel (Oracle) vulnerabilities
Ubuntu USN	USN-8876-1	Linux kernel (Azure CVM) vulnerabilities
Ubuntu USN	USN-8875-1	Linux kernel vulnerabilities
Ubuntu USN	USN-8877-1	Linux kernel (GCP) vulnerabilities
Ubuntu USN	USN-8878-1	Linux kernel (GCP) vulnerabilities
Ubuntu USN	USN-8879-1	Linux kernel (Oracle) vulnerabilities
Ubuntu USN	USN-8875-2	Linux kernel (NVIDIA) vulnerabilities
Ubuntu USN	USN-8917-1	Linux kernel vulnerabilities
Ubuntu USN	USN-8918-1	Linux kernel (Azure) vulnerabilities
Ubuntu USN	USN-9024-1	Linux kernel vulnerabilities
Ubuntu USN	USN-9025-1	Linux kernel vulnerabilities
Ubuntu USN	USN-9026-1	Linux kernel (Azure) vulnerabilities
Ubuntu USN	USN-9029-1	Linux kernel (Raspberry Pi) vulnerabilities
Ubuntu USN	USN-9040-1	Linux kernel (Low Latency NVIDIA) vulnerabilities
Ubuntu USN	USN-9066-1	Linux kernel (HWE) vulnerabilities

Metrics

No CVSS v4.0

Attack Vector Local

Attack Complexity Low

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.

Exploit prediction score: < 1% (0.169% probability within 30 days)

Exploitation none

Automatable no

Technical Impact partial

References

Link	Providers
https://git.kernel.org/stable/c/044167cba2384bcd783547ad5e30ecd292b30919
https://git.kernel.org/stable/c/3e6f007b43e2fc6546e21fa74ee62c38984a6672
https://git.kernel.org/stable/c/431ad239f2924dff337c3fccb9246597c1b63185
https://git.kernel.org/stable/c/478cdd736f2ce3114f90e775d7358136d3977b94
https://git.kernel.org/stable/c/6c9f29f128dd4057404838259af4c645318487e1
https://git.kernel.org/stable/c/70e4248793762df9832fd4fc2fc6ac7924572c36
https://git.kernel.org/stable/c/a8d87184576c889759e3aab899799a482f1e1a5b
https://git.kernel.org/stable/c/ed9b66905407eb3d02df1aaeed82eb7a7f0eb508
https://lore.kernel.org/linux-cve-announce/2026072559-CVE-2026-64271-b6b4@gregkh/T
https://nvd.nist.gov/vuln/detail/CVE-2026-64271
https://www.cve.org/CVERecord?id=CVE-2026-64271

History

Nov 7, 2026 7:30 AM Scoring metrics updated View changes

Type	Values Removed	Values Added
Metrics		ssvc `{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}`

Aug 13, 2026 6:45 PM Weaknesses updated. Scoring metrics updated View changes

Type	Values Removed	Values Added
Weaknesses		CWE-129
Metrics	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'}`	cvssV3_1 `{'score': 7.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}`

Aug 1, 2026 2:45 AM Weaknesses updated View changes

Type	Values Removed	Values Added
Weaknesses	CWE-787

Jul 29, 2026 12:15 PM Added references. Scoring metrics updated View changes

Type	Values Removed	Values Added
References		https://lore.kernel.org/linux-cve-announce/2026072559-CVE-2026-64271-b6b4@gregkh/T https://nvd.nist.gov/vuln/detail/CVE-2026-64271 https://www.cve.org/CVERecord?id=CVE-2026-64271
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`

Jul 26, 2026 3:00 AM Weaknesses updated View changes

Type	Values Removed	Values Added
Weaknesses		CWE-787

Jul 25, 2026 9:30 AM Description updated. Title updated. First appearance in the feed. Affected versions updated. Affected vendors updated. Added references View changes

Type	Values Removed	Values Added
Description		In the Linux kernel, the following vulnerability has been resolved: Input: touchwin - reset the packet index on every complete packet tw_interrupt() accumulates each non-zero serial byte into a fixed three-byte buffer with a running index that is only reset once a full packet has been received and the device's two Y bytes agree: tw->data[tw->idx++] = data; if (tw->idx == TW_LENGTH && tw->data[1] == tw->data[2]) { ... tw->idx = 0; } The reset is gated on tw->data[1] == tw->data[2], a value the device controls. A malicious, malfunctioning or counterfeit Touchwindow peripheral can stream non-zero bytes whose 2nd and 3rd bytes differ: the index reaches TW_LENGTH without the equality holding, is never reset, and keeps growing, so tw->data[tw->idx++] walks off the end of the three-byte array and the rest of the heap-allocated struct tw, one attacker-chosen byte at a time -- an unbounded, device-driven heap out-of-bounds write. Reset the index on every completed packet and report an event only when the two Y bytes match, like the other serio touchscreen drivers do.
Title		Input: touchwin - reset the packet index on every complete packet
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/044167cba2384bcd783547ad5e30ecd292b30919 https://git.kernel.org/stable/c/3e6f007b43e2fc6546e21fa74ee62c38984a6672 https://git.kernel.org/stable/c/431ad239f2924dff337c3fccb9246597c1b63185 https://git.kernel.org/stable/c/478cdd736f2ce3114f90e775d7358136d3977b94 https://git.kernel.org/stable/c/6c9f29f128dd4057404838259af4c645318487e1 https://git.kernel.org/stable/c/70e4248793762df9832fd4fc2fc6ac7924572c36 https://git.kernel.org/stable/c/a8d87184576c889759e3aab899799a482f1e1a5b https://git.kernel.org/stable/c/ed9b66905407eb3d02df1aaeed82eb7a7f0eb508