CVE-2026-55697: pnpm Code Execution via Malicious Config Dependencies

Technical summary

CVE-2026-55697 stems from improper handling of configDependencies in pnpm-workspace.yaml files. Prior to the patched versions, pnpm would resolve and execute platform-specific binaries from @pacquet/<platform>-<arch>/pacquet packages stored in node_modules/.pnpm-config before normal command dispatch. An attacker can inject malicious pacquet or @pnpm/pacquet entries as repository-declared dependencies, causing pnpm to spawn untrusted executables with the privileges of the installing user or CI process. The vulnerability chains CWE-494 (Download of Code Without Integrity Check), CWE-78 (OS Command Injection), and CWE-829 (Inclusion of Functionality from Untrusted Control Sphere), reflecting the attack's progression from dependency confusion through code execution.

Business impact

This vulnerability directly threatens supply-chain security for JavaScript development teams. Any developer or CI/CD pipeline that clones and installs a malicious repository faces immediate code execution risk, potentially leading to credential theft, source code exfiltration, build artifact manipulation, or lateral movement within development infrastructure. Organizations relying on pnpm for monorepo management, containerized development, or automated deployments are particularly exposed. The risk is amplified in open-source contribution workflows where external contributors can introduce compromised repositories.

Affected systems

pnpm versions prior to 10.34.2 (in the 10.x line) and prior to 11.5.3 (in the 11.x line) are vulnerable. Any system running these versions—including developer workstations, CI/CD runners (GitHub Actions, GitLab CI, Jenkins, etc.), and containerized build environments—is at risk when installing dependencies from untrusted or compromised repositories.

Exploitability

Exploitation requires that a user or automated system runs `pnpm install` on a repository controlled or modified by the attacker. The CVSS vector (AV:N/AC:H/PR:N/UI:R/S:U) indicates network-adjacent attack with high complexity and user interaction required, meaning the attacker cannot force installation—the victim must clone or access the repository. However, in CI/CD contexts where repositories are automatically checked out and built, this barrier is substantially lowered. No known public exploit exists yet, and the vulnerability has not been added to the KEV catalog.

Remediation

Immediately upgrade pnpm to version 10.34.2 or later (for the 10.x series) or 11.5.3 or later (for the 11.x series). Organizations using pnpm should prioritize upgrades in CI/CD pipelines first, as these are the highest-risk environments. For development workstations, establish a policy requiring the latest patched version before resuming work with untrusted repositories.

Patch guidance

Verify the patched versions against the official pnpm release notes or GitHub repository. For npm-installed pnpm, run `npm install -g pnpm@latest` or specify the minimum safe version. For package.json-managed pnpm versions, update the package.json constraint and reinstall. Container images and CI/CD configurations that pin pnpm versions should be updated to reflect 10.34.2+ or 11.5.3+. Test patches in a staging environment before broad rollout, particularly for locked monorepo setups.

Detection guidance

Monitor pnpm version usage across development and CI environments using dependency audits or version-scanning tools. Detect installations from untrusted repositories by reviewing git clone logs and source repository metadata in CI logs. Watch for unexpected process spawning of binaries from node_modules/.pnpm-config during `pnpm install` phases, particularly binaries with platform-specific naming patterns. Endpoint detection tools should flag execution of unfamiliar @pacquet binaries or references to unusual node_modules subdirectories during package installation workflows.

Why prioritize this

HIGH priority. The vulnerability combines ease of supply-chain manipulation with direct code execution under developer or CI privileges. The attack surface is broad—any pnpm user installing from an untrusted source is at risk—and the impact spans confidentiality, integrity, and availability. While user interaction is required, automated CI/CD systems reduce the friction of exploitation.

Risk score, explained

CVSS 7.5 (HIGH) reflects high impact across confidentiality, integrity, and availability (the attacker can exfiltrate data, modify source or artifacts, and disrupt builds) balanced against higher complexity and user interaction requirements. In automated CI environments, the practical risk is elevated beyond the base score.

Frequently asked questions