GHSA-fw99-f933-rgh8 — opencv-python
HIGHGHSA-fw99-f933-rgh8 is a high-severity (CVSS 7.5) Out-of-bounds Read vulnerability in opencv-python. 1 public exploit reference exists, so weaponization risk is real. A fix is available for opencv-python — see the affected versions and patch details below.
Out-of-bounds Read and Out-of-bounds Write 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-fw99-f933-rgh8 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 379,145 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/write in the function HaarEvaluator::OptFeature::calc in modules/objdetect/src/cascadedetect.hpp, which leads to denial of service.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | opencv-python | all versions | 3.4.7.28pip install --upgrade 'opencv-python==3.4.7.28' |
| 🐍PyPI | opencv-python | ≥ 4.0.0.21&&< 4.1.1.26 | 4.1.1.26pip install --upgrade 'opencv-python==4.1.1.26' |
| 🐍PyPI | opencv-python-headless | all versions | 3.4.7.28pip install --upgrade 'opencv-python-headless==3.4.7.28' |
| 🐍PyPI | opencv-python-headless | ≥ 4.0.0.21&&< 4.1.1.26 | 4.1.1.26pip install --upgrade 'opencv-python-headless==4.1.1.26' |
| 🐍PyPI | opencv-contrib-python | all versions | 3.4.7.28pip install --upgrade 'opencv-contrib-python==3.4.7.28' |
| 🐍PyPI | opencv-contrib-python | ≥ 4.0.0.21&&< 4.1.1.26 | 4.1.1.26pip install --upgrade 'opencv-contrib-python==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, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
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-fw99-f933-rgh8 is resolved across your whole dependency graph.
Workarounds
Constrain what reaches the vulnerable code: limit the size and shape of untrusted input, isolate the affected component in a sandboxed or least-privileged process, and enable the platform's memory-safety mitigations (ASLR, stack protector, hardened allocator) so an out-of-bounds access is more likely to fail closed than to be exploitable.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-fw99-f933-rgh8 can be triaged on real exposure rather than presence alone.
Tailored to GHSA-fw99-f933-rgh8. 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.
The versions of OpenCV as shipped with Red Hat Enterprise Linux 7 and 8 are affected by this flaw. Although it's technically possible that classifiers are loaded from untrusted sources, this is probably an unlikely case in practice.
Avoid loading cascade classifiers from external untrusted sources.Source: Red Hat security advisory for GHSA-fw99-f933-rgh8 (CC BY 4.0)
Frequently Asked Questions
Is GHSA-fw99-f933-rgh8 in your dependencies?
O3 Security finds GHSA-fw99-f933-rgh8 across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.