GHSA-j44v-mmf2-xvm9 is a high-severity (CVSS 7.8) Improper Input Validation vulnerability in pdm. 1 public exploit reference exists, so weaponization risk is real. No vendor fix is recorded yet; mitigation options are listed below.
PDM Trojan Lockfile
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-j44v-mmf2-xvm9.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
GHSA-j44v-mmf2-xvm9 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,636 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
pdmReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
Summary
It's possible to craft a malicious pdm.lock file that could allow e.g. an insider or a malicious open source project to appear to depend on a trusted PyPI project, but actually install another project.
Details
Project foo can be targeted by creating the project foo-2 and uploading the file foo-2-2.tar.gz to pypi.org. PyPI will see this as project foo-2 version 2, while PDM will see this as project foo version 2-2. The version must only be parseable as a version (and the filename must be a prefix of the project name), but it's not verified to match the version being installed. (Version 2-2 is also not a valid normalized version per PEP 440.)
Matching the project name exactly (not just prefix) would fix the issue. The version should also be verified to avoid version downgrade attacks.
PoC
Example pdm.lock snippet to appear to depend on foo but actually install foo-2
"foo 2.2.0" = [
url = "https://files.pythonhosted.org/.../foo-2-2.tar.gz
]
Impact
When installing dependencies with PDM, what's actually installed could differ from what's listed in pyproject.toml (including arbitrary code execution on install). It could also be used for downgrade attacks by only changing the version.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | pdm | all versions | No fix |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for pdm, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Remediation status
No patched version of pdm has shipped for GHSA-j44v-mmf2-xvm9 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-j44v-mmf2-xvm9 can be triaged on real exposure rather than presence alone.
Tailored to GHSA-j44v-mmf2-xvm9. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-j44v-mmf2-xvm9 in your dependencies?
O3 Security finds GHSA-j44v-mmf2-xvm9 across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.