CVE-2018-5269 is a medium-severity (CVSS 5.5) Reachable Assertion 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.
Reachable Assertion in OpenCV.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2018-5269 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 385,987 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
opencv-python🐍opencv-contrib-pythonReal-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
In OpenCV 3.3.1 (corresponds with OpenCV-Python 3.3.1.11), an assertion failure happens in cv::RBaseStream::setPos in modules/imgcodecs/src/bitstrm.cpp because of an incorrect integer cast.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | opencv-python | all versions | 3.4.1.15pip install --upgrade 'opencv-python==3.4.1.15' |
| 🐍PyPI | opencv-contrib-python | all versions | 3.4.1.15pip install --upgrade 'opencv-contrib-python==3.4.1.15' |
Affected Products
debian linuxdebianopencvopencvResearch 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 3.4.1.15 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2018-5269 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.
Frequently Asked Questions
Is CVE-2018-5269 in your dependencies?
Find it across PyPI, including transitive dependencies.