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Vulnerability

CVE-2026-63902

Reference data from vuln.mlab.sh, coverage from our own index.

CVSS
5.5 Medium
Vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS
0.22%
Risk score
6.8
Published
2026-07-19
Status
Published

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 ] A flaw was found in the Linux kernel's `cypress_m8` USB serial driver. This vulnerability allows a local attacker to cause a denial of service (DoS) due to an out-of-bounds read. The `cypress_read_int_callback()` function does not properly validate the length of interrupt packets, leading to attempts to read beyond allocated memory when processing malformed short reports. This can result in system instability.

Weaknesses

CWE-125

Coverage 5

Advisories and references