Affected: pnpm

pnpm is a package manager. From 11.3.0 until 11.5.3, `pnpm stage download` derived a local filename from registry-controlled package name and version fields. A crafted manifest could escape the selected download directory and overwrite another reachable file. The merged fix validates both fields, derives one safe filename, and verifies the final destination before writing. This vulnerability is fixed in 11.5.3.

Affected: npm: pnpm

## Summary

The staged-tarball filename traversal reported as GHSA-v23m-ccfg-pq9h / CAND-PNPM-038 is fixed on `main` by [pnpm/pnpm#12303](https://github.com/pnpm/pnpm/pull/12303), merged as `65443f4bdf1f0db9c8c7dc58fee25252607e9234`.

Before the fix, `pnpm stage download` derived a local filename from registry-controlled package name and version fields. A crafted manifest could escape the selected download directory and overwrite another reachable file. The merged fix validates both fields, derives one safe filename, and verifies the final destination before writing.

## Security boundary

- Package names and semantic versions are validated before they can influence a local filename. - POSIX and Windows path separators are rejected by basename checks. - Stage download and tarball summary paths use the same filename helper. - The resolved output path must remain an immediate child of the selected download directory. - The stage identifier is already constrained to a UUID.

## Exploit replay

Before `65443f4bdf`, a traversal-bearing manifest version could make the command write outside the selected directory. After the fix, malicious package names fail with `ERR_PNPM_INVALID_PACKAGE_NAME`, malicious versions fail with `ERR_PNPM_INVALID_PACKAGE_VERSION`, no outside file is created, and the download directory remains empty.

## Files changed

- `releasing/commands/src/tarball/safeTarballFilename.ts` validates manifest identity and rejects cross-platform path separators. - `relea…