Out-of-bounds write in Linux kernel - CVE-2026-63957
Published: July 20, 2026
Vulnerability identifier: #VU138694
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-2026-63957
CWE-ID: CWE-787
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 an attacker with physical access to cause memory corruption.
The vulnerability exists due to memory corruption in the safe_serial USB serial driver when processing a malicious USB device that reports a bulk-out endpoint size smaller than eight bytes in safe mode. An attacker with physical access can connect a crafted USB device to cause memory corruption.
Exploitation requires the target system to interact with a malicious USB device operating in safe mode.
How to mitigate CVE-2026-63957
Install security update from vendor's repository.
Sources
- https://git.kernel.org/stable/c/161ea0e5236f5f051d2d85d6c54dd08ee9dc7ba4
- https://git.kernel.org/stable/c/438061ed1ad85e6743e2dce826671772d81089ec
- https://git.kernel.org/stable/c/857b3cc73f91871ae4433f8b97c4670b78f8dc96
- https://git.kernel.org/stable/c/9b3145b3001fb24de1da72d1deb0bea70e5a078b
- https://git.kernel.org/stable/c/a550ed2117ca4709d38f713933ff924a83942e41
- https://git.kernel.org/stable/c/c7336c0fba5c959249f3d793d33076b992ec3ee4
- https://git.kernel.org/stable/c/e3a1d6eee25dc96b1d2db0ecd9d8741e92056476
- https://git.kernel.org/stable/c/f793b67d41e5fab719c5a90baa77cbd2fe259517