CVE-2026-28525: SWUpdate Integer Underflow in Multipart Upload Parser

SWUpdate contains an integer underflow vulnerability in the multipart upload parser in mongoosemultipart.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 mghttpmultipartcontinuewaitforchunk() 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.