Integer overflow in Linux kernel - CVE-2026-63896
Published: July 20, 2026
Vulnerability identifier: #VU138749
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-63896
CWE-ID: CWE-190
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vendor: Linux Foundation
Affected software:
Linux kernel
Linux kernel
Detailed vulnerability description
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to an integer underflow leading to an out-of-bounds write in the WebUSB GET_URL handler in composite_setup() when processing a crafted USB SETUP packet. A remote attacker can send a specially crafted USB request to cause a denial of service.
Exploitation is possible against gadgets with webusb/use=1 and a landing page configured.
How to mitigate CVE-2026-63896
Install security update from vendor's repository.
Sources
- https://git.kernel.org/stable/c/046870ff6b6f7b743c953c061043a9b30700d491
- https://git.kernel.org/stable/c/6c5dbc104dadd79fc2923497c20bae759a18758c
- https://git.kernel.org/stable/c/a20f0ccf45708af6e063c7234c215d364b00de25
- https://git.kernel.org/stable/c/f5869dfaa89854dcf34121036294d42d6c7acb8f
- https://git.kernel.org/stable/c/f8f5a8f48c7cae3fac85e04b593bd47939f9725f