GHSA-fm39-cw8h-3p63
HIGHGHSA-fm39-cw8h-3p63 is a high-severity (CVSS 8.2) Out-of-bounds Read vulnerability in opencv-python. 1 public exploit reference exists, so weaponization risk is real. O3 Security confirms whether GHSA-fm39-cw8h-3p63 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Out-of-bounds Read in OpenCV
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-fm39-cw8h-3p63 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 0 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
opencv-python🐍opencv-python🐍opencv-python-headless🐍opencv-python-headless🐍opencv-contrib-python🐍opencv-contrib-python🐍opencv-contrib-python-headless🐍opencv-contrib-python-headlessReal-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
An issue was discovered in OpenCV before 3.4.7 and 4.x before 4.1.1 (OpenCV-Python before 3.4.7.28 and 4.x before 4.1.1.26). There is an out of bounds read in the function cv::predictOrderedcv::HaarEvaluator in modules/objdetect/src/cascadedetect.hpp, which leads to denial of service.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | opencv-python | all versions | 3.4.7.28 |
| 🐍PyPI | opencv-python | ≥ 4.0.0.21&&< 4.1.1.26 | 4.1.1.26 |
| 🐍PyPI | opencv-python-headless | all versions | 3.4.7.28 |
| 🐍PyPI | opencv-python-headless | ≥ 4.0.0.21&&< 4.1.1.26 | 4.1.1.26 |
| 🐍PyPI | opencv-contrib-python | all versions | 3.4.7.28 |
| 🐍PyPI | opencv-contrib-python | ≥ 4.0.0.21&&< 4.1.1.26 | 4.1.1.26 |
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 opencv-python. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update opencv-python to 3.4.7.28 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-fm39-cw8h-3p63 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 pinpoints whether GHSA-fm39-cw8h-3p63 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-fm39-cw8h-3p63. 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.
Frequently Asked Questions
Is GHSA-fm39-cw8h-3p63 in your dependencies?
O3 detects GHSA-fm39-cw8h-3p63 across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.