CVE-2021-3678 is a medium-severity (CVSS 5.9) CWE-338 vulnerability in showdoc/showdoc. A fix is available for showdoc/showdoc — see the affected versions and patch details below.
Use of Cryptographically Weak Pseudo-Random Number Generator in showdoc
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2021-3678 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
showdoc/showdocReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
showdoc is vulnerable to Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | showdoc/showdoc | all versions | 2.9.8composer require showdoc/showdoc:^2.9.8 |
Affected Products
showdocshowdocDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for showdoc/showdoc, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update showdoc/showdoc to 2.9.8 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-3678 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-2021-3678 in your dependencies?
Find it across Packagist, including transitive dependencies.