CVE-2026-82393: pnpm: A tarball dependency's manifest `name` escapes node_modules → arbitrary file write/overwrite on install

When resolving a package, pnpm uses the resolved manifest name as a raw path segment for the isolated-linker import target. A tarball dependency whose package.json name is a scoped path traversal (@x/../../…/<abs path>) is therefore extracted outside node_modules, to an attacker-chosen absolute path, and can overwrite existing files there. Attacker controls the destination, filenames, and contents → arbitrary file write → code execution (e.g. ~/.zshrc, .git/hooks/pre-commit, another package’s code). Occurs during pnpm install even with --ignore-scripts (no lifecycle scripts run), defeating that safety.

Same class as the just-patched GHSA-hwx4 (transitive-dependency alias traversal) and GHSA-v23m (stage download manifest name/version traversal), in a sink their fixes did not cover: the isolated-linker import target keyed by the resolved name.