CVE-2026-47764 pdm-project CVE debrief

Who should care

Defenders responsible for Python package management and dependency management using pdm should assess exposure and prioritize upgrading to version 2.27.0 or later. This includes operators, platform administrators, vulnerability management teams, and security teams who use pdm for managing Python packages and dependencies. They should review the vulnerability details and plan for an upgrade to mitigate the risk of arbitrary file writes through path-travers.

Why it matters

Defenders should care about CVE-2026-47764 because it allows for path traversal and potential arbitrary file writes in the pdm Python package manager, impacting Python package management and dependency management.

• Potential for arbitrary file writes
• Risk of compromise through malicious wheel usage
• Need for validation of paths in write_to_fs function
• Priority for upgrading to fixed version 2.27.0

Technical summary

The pdm package and dependency manager for Python has a vulnerability in versions prior to 2.27.0. The InstallDestination.write_to_fs() function in src/pdm/installers/installers.py does not properly validate paths, allowing for traversal attacks. A malicious wheel with traversal entries can write arbitrary files. The issue arises from the replacement of the safe _path_with_destdir() with a bare os.path.join() that performs no path validation. This vulnerability impacts Python package management and dependency management.

Defensive priority

Defenders should prioritize upgrading to pdm version 2.27.0 or later to mitigate this vulnerability.

Recommended defensive actions

• Upgrade to pdm version 2.27.0 or later
• Review and validate the paths used in the write_to_fs function
• Monitor for suspicious activity related to pdm package usage
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented

Evidence notes

The vulnerability exists in versions prior to 2.27.0 of the pdm package. The issue arises from the InstallDestination.write_to_fs() function, which does not properly validate paths, allowing for traversal attacks.

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.