CVE-2026-28525

CVE-2026-28525 is a high-severity vulnerability rated 8.2/10 on the CVSS scale. SWUpdate contains an integer underflow vulnerability in the multipart upload parser in mongoose_multipart.c that allows unauthenticated attackers to cause a denial of service by sending a crafted HTTP POST request to /upload with a malformed multipart boundary and controlled TCP stream timing. Attackers can trigger an integer underflow in the mg_http_multipart_continue_wait_for_chunk() function when the buffer length falls within a specific range, causing an out-of-bounds heap read past the allocated receive buffer to a local IPC socket.. EPSS estimates a 0.32% chance of exploitation in the next 30 days.