A vulnerability in the Linux kernel’s fpga:microchip-spi driver routine mpf_ops_parse_header() causes an out‑of‑bounds read when the header size read from the bitstream is zero. The parser then accesses a byte before the start of the buffer, which can expose arbitrary kernel data to a reader. This flaw arises from insufficient input validation of the header_size field and represents a classic OOB read weakness.

The flaw affects Linux kernel builds that incorporate the fpga:microchip-spi driver without the published patch. All distributions relying on the default driver in the kernel tree are susceptible until the kernel is upgraded to a revised version that returns -EINVAL for a zero header_size.

While there is no EPSS score or CVSS rating reported, the vulnerability is not listed in the CISA KEV catalog, suggesting no known active exploitation yet. An attacker would need to supply a crafted bitstream that the fpga-mgr core processes, meaning the attack vector is likely local or requires privileged access to the FPGA subsystem. As reading kernel memory may lead to information disclosure or facilitate further privilege escalation, the risk is considered moderate pending patch deployment.