Analysis of CVE-2026-109618: PHP use-after-free via PS(id)

A breakdown of CVE-2026-109618 in PHP: during progress-tracked file uploads, an uncleaned PS(id) pointer after abnormal request termination can leak process memory. The root cause is a stale cache and missing graceful termination handling.

• PS(id) is not cleaned up when an upload request terminates abnormally
• A later request can derive its sessionID from another request's memory
• The flaw enables disclosure of process memory contents