CVE-2026-47121 Sparkle: Binary delta apply intermediate-symlink traversal in malicious .delta

Sparkle is a software update framework for macOS. Prior to version 2.9.2, Autoupdate/SUBinaryDeltaApply.m enforces relativePath.pathComponents containsObject:@".." and rejects writes whose immediate parent directory IS itself a symbolic link, but does not detect symlinks deeper in the relative...