Out-of-bounds write in Linux kernel - CVE-2026-64366

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Main Vulnerability Database Vulnerabilities #VU139601

Out-of-bounds write in Linux kernel - CVE-2026-64366

Published: July 27, 2026


Vulnerability identifier: #VU139601
CSH Severity: Low
CVSS v4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-64366
CWE-ID: CWE-787
Exploitation vector: Local access
Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a local user to cause a denial of service or execute arbitrary code.

The vulnerability exists due to an out-of-bounds write in wacom_wac_queue_insert in the Wacom HID driver when processing crafted input reports. A local user can send a specially crafted report to cause a denial of service or execute arbitrary code.

The issue is triggered when stale data in an empty kfifo is interpreted as a record length, corrupting the internal fifo state before a memcpy writes past a 256-byte buffer.


Affected software

Linux kernel
Ubuntu
linux (Ubuntu package)
linux-realtime (Ubuntu package)
linux-gcp (Ubuntu package)
linux-aws (Ubuntu package)
linux-oracle (Ubuntu package)
linux-raspi (Ubuntu package)
linux-azure (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-ibm (Ubuntu package)
linux-nvidia-bos (Ubuntu package)
linux-hwe-7.0 (Ubuntu package)
linux-oracle-7.0 (Ubuntu package)
linux-gcp-7.0 (Ubuntu package)
linux-azure-7.0 (Ubuntu package)
linux-oem-7.0 (Ubuntu package)
linux-gke (Ubuntu package)
linux-aws-7.0 (Ubuntu package)
linux-nvidia-7.0 (Ubuntu package)

How to mitigate CVE-2026-64366

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux (Ubuntu package) - update to 7.0.0-31.31
linux-realtime (Ubuntu package) - update to 7.0.0-31.31.1
linux-gcp (Ubuntu package) - update to 7.0.0-1011.11
linux-aws (Ubuntu package) - update to 7.0.0-1012.12
linux-oracle (Ubuntu package) - update to 7.0.0-1011.11
linux-raspi (Ubuntu package) - update to 7.0.0-1019.19
linux-azure (Ubuntu package) - update to 7.0.0-1014.14
linux-nvidia (Ubuntu package) - update to 7.0.0-1018.18
linux-ibm (Ubuntu package) - update to 7.0.0-1013.13
linux-nvidia-bos (Ubuntu package) - update to 7.0.0-2018.18
linux-hwe-7.0 (Ubuntu package) - update to 7.0.0-31.31~24.04.1
linux-oracle-7.0 (Ubuntu package) - update to 7.0.0-1011.11~24.04.1
linux-gcp-7.0 (Ubuntu package) - update to 7.0.0-1011.11~24.04.1
linux-azure-7.0 (Ubuntu package) - update to 7.0.0-1014.14~24.04.1
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1013.13
linux-gke (Ubuntu package) - update to 7.0.0-1006.7
linux-aws-7.0 (Ubuntu package) - update to 7.0.0-1012.12~24.04.1
linux-nvidia-7.0 (Ubuntu package) - update to 7.0.0-1018.18~24.04.1

External References

Related Security Bulletins