CVE-2026-88018 rclone serve s3: --auth-proxy without --auth-key authenticates nobody - full SigV4 signature bypass

rclone is a command-line program to sync files and directories to and from different cloud storage providers. Prior to 1.75.1, rclone serve s3 configured with --auth-proxy but without --auth-key allows authPairMiddleware to register any client-chosen accessKeyID with an empty ws.s3Secret. gofakes...