CVE-2020-7658 is a medium-severity (CVSS 6.1) CWE-444 vulnerability in meinheld. A fix is available for meinheld — see the affected versions and patch details below.
meinheld vulnerable to HTTP Request Smuggling
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
meinheldReal-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
meinheld prior to 1.0.2 is vulnerable to HTTP Request Smuggling. HTTP pipelining issues and request smuggling attacks might be possible due to incorrect Content-Length and Transfer encoding header parsing.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | meinheld | all versions | 1.0.2pip install --upgrade 'meinheld==1.0.2' |
Affected Products
meinheldmeinheldDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for meinheld, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update meinheld to 1.0.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-7658 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-2020-7658 in your dependencies?
Find it across PyPI, including transitive dependencies.