GHSA-3936-cmfr-pm3m is a high-severity (CVSS 7.5) Path Traversal vulnerability in black. A fix is available for black — see the affected versions and patch details below.
Black: Arbitrary file writes from unsanitized user input in cache file name
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- 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-3936-cmfr-pm3m.
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-3936-cmfr-pm3m 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 378,156 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
blackReal-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
Impact
Black writes a cache file, the name of which is computed from various formatting options. The value of the --python-cell-magics option was placed in the filename without sanitization, which allowed an attacker who controls the value of this argument to write cache files to arbitrary file system locations.
Patches
Fixed in Black 26.3.1.
Workarounds
Do not allow untrusted user input into the value of the --python-cell-magics option.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | black | ≥ 24.3.0&&< 26.3.1 | 26.3.1pip install --upgrade 'black==26.3.1' |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for black, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update black to 26.3.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-3936-cmfr-pm3m is resolved across your whole dependency graph.
Workarounds
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-3936-cmfr-pm3m can be triaged on real exposure rather than presence alone.
Tailored to GHSA-3936-cmfr-pm3m. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat Ansible Automation Platform 2.5 | ansible-automation-platform-25/hub-rhel8:1777393635 | RHSA-2026:13553 |
| Red Hat Ansible Automation Platform 2.6 | ansible-automation-platform-26/ansible-dev-tools-rhel9:1777390240 | RHSA-2026:13545 |
| Red Hat OpenShift AI 2.25 | rhoai/odh-workbench-jupyter-datascience-cpu-py312-rhel9:1776319193 | RHSA-2026:10184 |
Frequently Asked Questions
Is GHSA-3936-cmfr-pm3m in your dependencies?
O3 Security finds GHSA-3936-cmfr-pm3m across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.