SEPTEMBER 8, 2026
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Case File

CVE-2026-63902

UNKNOWN · CVSS N/A EPSS 0.21%

Source: NVD + CISA KEV + EPSS · Published 2026-07-19 · Last synced 2026-08-18

CyberRota Analysis

AI-Generated

The vulnerability affects the Linux kernel's handling of interrupt packets from Cypress USB serial devices, specifically in the `cypress_read_int_callback()` function, which may lead to out-of-bounds reads due to improper validation of packet headers. This could potentially allow an attacker to exploit malformed packets, leading to undefined behavior or crashes in the affected systems. Organizations using Linux with Cypress USB serial devices should prioritize addressing this issue to mitigate potential security risks.

CVE
CVE-2026-63902
Severity
UNKNOWN
CVSS
N/A
EPSS
0.21%
Linux

Original NVD Description

In the Linux kernel, the following vulnerability has been resolved: USB: serial: cypress_m8: validate interrupt packet headers cypress_read_int_callback() parses the interrupt-in buffer according to the selected Cypress packet format. Format 1 has a two-byte status/count header and format 2 has a one-byte combined status/count header. The usb-serial core sizes the interrupt-in buffer from the endpoint descriptor's wMaxPacketSize, and successful interrupt transfers can complete short when URB_SHORT_NOT_OK is not set. Check that the completed packet contains the selected header before reading it. Malformed short reports are ignored and the interrupt URB is resubmitted through the existing retry path, preventing out-of-bounds header-byte reads. KASAN report as below: KASAN slab-out-of-bounds in cypress_read_int_callback+0x240/0x7f0 Read of size 1 Call trace: cypress_read_int_callback() (drivers/usb/serial/cypress_m8.c:1009) __usb_hcd_giveback_urb() dummy_timer() [ johan: use constants in header length sanity checks ]