CVE Catalog

CVE-2026-63902

Low risk· EPSS 11%
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.21%

11th percentile - higher than 11% of all known CVEs

Summary

In the Linux kernel's cypress_m8 USB serial driver, a vulnerability allows out-of-bounds read due to missing validation of interrupt packet headers. The cypress_read_int_callback() function did not check if the received packet contains the required header before reading it, which can lead to out-of-bounds memory access on short transfers.

Risk Assessment

An attacker with physical USB access can send a crafted packet causing a slab-out-of-bounds read, potentially leading to sensitive data disclosure or system crash.

Recommendation

Immediately update the Linux kernel to a version containing the fix (commit addressing the issue). If updating is not possible, restrict physical access to USB ports on production systems.

Other vulnerabilities in Linux kernel

See all
Original NVD description (English source)

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 ]

Vulnerability data from NVD (NIST) · CISA KEV · EPSS