CVE-2026-101043 pnpm CVE debrief

Who should care

Defenders responsible for managing pnpm installations, developers using pnpm in their projects, and security teams monitoring for suspicious activity related to pnpm commands and proxy settings should be aware of this vulnerability.

Why it matters

The CVE-2026-101043 vulnerability in pnpm allows an attacker to cause a victim to expand environment secrets into a proxy hostname or userinfo, potentially leading to exfiltration of sensitive information. Defenders should prioritize verifying and remediating pnpm installations, reviewing and restricting access to repository-controlled pnpm-workspace.yaml files, and monitoring for suspicious activity related to pnpm commands and proxy settings.

• Potential exfiltration of environment secrets
• Possible unauthorized access to sensitive information
• Need for verification of pnpm installations and proxy settings
• Requirement for restricted access to repository-controlled pnpm-workspace.yaml files

Technical summary

The pnpm package manager is vulnerable to environment variable exfiltration via proxy settings. An attacker can cause a victim to expand environment secrets into a proxy hostname or userinfo by controlling a repository's pnpm-workspace.yaml file. This vulnerability affects pnpm versions 11.0.0 before 11.11.0 and 10.7.0 before 10.34.5. The vulnerability allows an attacker to potentially exfiltrate sensitive information by routing install traffic through an attacker-controlled host. The issue arises from the expansion of ${VAR} environment-variable placeholders in httpProxy, httpsProxy, and noProxy settings.

Defensive priority

Defenders should prioritize verifying and remediating pnpm installations to prevent potential environment variable exfiltration.

Recommended defensive actions

• Verify pnpm installations and ensure they are updated to a fixed version.
• Review and restrict access to repository-controlled pnpm-workspace.yaml files.
• Monitor for suspicious activity related to pnpm commands and proxy settings.
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up.
• Review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance.
• Plan vendor-supported updates or mitigations through normal change control where exposure is confirmed.
• Check relevant monitoring, detection, and logs for exposed assets that need extra review.

Evidence notes

The CVE record and source references provide details on the vulnerability in pnpm versions 11.0.0 before 11.11.0 and 10.7.0 before 10.34.5. The vulnerability allows an attacker to cause a victim to expand environment secrets into a proxy hostname or userinfo.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.