pnpm 11.0.0 before 11.11.0 Environment Variable Exfiltration via Proxy Settings (CVE-2026-101043)

The vulnerability in pnpm versions 11.0.0 before 11.11.0 and 10.7.0 before 10.34.5 arises because the httpProxy, httpsProxy, and noProxy settings in pnpm-workspace.yaml expand environment-variable placeholders (${VAR}) without proper suppression for untrusted manifests. Since the manifest is repository-controlled and proxy keys were omitted from the suppression mechanism, an attacker controlling the pnpm-workspace.yaml can inject environment variables like NPM_TOKEN or GITHUB_TOKEN into proxy configuration. This causes the victim's pnpm commands (e.g., pnpm install) to send traffic and DNS lookups through attacker-controlled proxy hosts, leaking sensitive environment secrets. The exfiltration happens early during configuration loading, prior to lifecycle script execution. The vulnerability is addressed by suppressing placeholder expansion for proxy keys and fixed in versions 11.11.0 and 10.34.5.

An attacker who controls a repository's pnpm-workspace.yaml can exfiltrate sensitive environment variables such as NPM_TOKEN or GITHUB_TOKEN from a victim's environment by manipulating proxy settings. This leads to potential credential leakage and unauthorized access to services relying on these tokens. The exfiltration occurs transparently during configuration loading, without requiring execution of lifecycle scripts, increasing the risk of unnoticed compromise.

A fix is available and has been released in pnpm versions 11.11.0 and 10.34.5. Users should upgrade to these versions or later to mitigate this vulnerability. Until upgraded, avoid running pnpm commands on repositories with untrusted pnpm-workspace.yaml files or ensure that environment variables containing secrets are not exposed in proxy settings.