CVE-2021-3990: showdoc is vulnerable to Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)

medium Affects showdoc/showdoc. Feed 2026.10.29.1, updated 2026-10-28; published ; advisory modified .

showdoc is vulnerable to Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)

Package
showdoc/showdoc Composer
Affected versions
<2.9.13
Fixed in
2.9.13
Severity
medium  CVSS 6.5
Exploitation
not on CISA KEV · EPSS 1% (59.3th percentile)
Published
2021-12-03
Source
osv.dev

References

CWE-338
NVD recordshowdoc/showdoc advisories

Am I affected?

Find out in one command. phpwarden checks your composer.lock against this advisory and 20,000+ others, ranked by real-world exploitation (CISA KEV + EPSS). Free, offline, open data.

# PHP projects (recommended)
composer require --dev phpwarden/phpwarden
# then
vendor/bin/phpwarden deps composer.lock

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