Disclosures
STMicroelectronics · STM32Cube USB Host Library / PTP-MTP
USB Host PTP 32-Bit Array Length Out-of-Bounds Write
SecMateSECMATE-2026-0029
VendorSTMicroelectronics
ProductSTM32Cube USB Host Library / PTP-MTP
Advisories
Timeline
Reported
Jan 2, 2026
Fixed
Jun 25, 2026
Published
Jul 2, 2026
Summary
STM32Cube USB Host Library 3.5.4 and earlier trusts device-supplied lengths while decoding PTP 32-bit arrays into fixed-size destination arrays. A malicious PTP/MTP device can return oversized Storage ID or Object Handle arrays and trigger out-of-bounds writes, causing memory corruption or a host crash. ST fixed the issue in USB Host Library 3.5.5.