CVE-2026-24056: pnpm has symlink traversal in file:/git dependencies

When pnpm installs a file: (directory) or git: dependency, it follows symlinks and reads their target contents without constraining them to the package root. A malicious package containing a symlink to an absolute path (e.g., /etc/passwd, ~/.ssh/id_rsa) causes pnpm to copy that file’s contents into node_modules, leaking local data.

Preconditions: Only affects file: and git: dependencies. Registry packages (npm) have symlinks stripped during publish and are NOT affected.