Out-of-bounds read in Linux kernel - CVE-2026-63903
Published: July 20, 2026
Vulnerability identifier: #VU138739
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-63903
CWE-ID: CWE-125
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 local attacker to disclose sensitive information.
The vulnerability exists due to an out-of-bounds read in the belkin_sa_read_int_callback() USB serial interrupt handler when processing short successful interrupt transfers. A local attacker can trigger the driver to parse a crafted short interrupt packet to disclose sensitive information.
The issue occurs because the handler treats interrupt data as a four-byte status report and reads status fields at offsets 2 and 3 even when the completed packet is shorter.
How to mitigate CVE-2026-63903
Install security update from vendor's repository.
Sources
- https://git.kernel.org/stable/c/22823a319fb2afdf02cacafbed8b613b757efbc8
- https://git.kernel.org/stable/c/37e54d1b986df35c936d81e5b59a7aa3ec6938f0
- https://git.kernel.org/stable/c/4ce058df2ee02cc2a0f0fd5cd64ce6f1482a0b65
- https://git.kernel.org/stable/c/6a4602221cba7a738442328d66a2f0b1c9bf6e17
- https://git.kernel.org/stable/c/db1e7eb6203d534dad64cac2c793b69e561e657b
- https://git.kernel.org/stable/c/f1617539ab90e67da788959bfd314076f093a11a
- https://git.kernel.org/stable/c/f361359a952da15e70e693c2d7dca5c5843eae3e
- https://git.kernel.org/stable/c/ffb739a49186ea784bbd9cb91b647f062395b419