CVE-2021-3990
Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG) in star7th/showdoc
showdoc is vulnerable to Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- Low
- Availability
- Low
Exploit likelihood
What each source reports
CVE List Score used
Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG) in star7th/showdoc
showdoc is vulnerable to Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)
- Record
CVE-2021-3990- CVSS 3.0
- 6.5 Medium
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:L - Weakness
- CWE-338
- Updated
- 2026-11-02
EUVDEUVD-2021-2596
showdoc is vulnerable to Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)
- Record
EUVD-2021-2596- CVSS 3.0
- 6.5 Medium
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:L - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-vrgh-5w3c-ggf8
showdoc is vulnerable to Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)
showdoc is vulnerable to Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG).
- Record
GHSA-vrgh-5w3c-ggf8- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N - Weakness
- CWE-338
- Updated
- 2026-11-02
NVD
showdoc is vulnerable to Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)
- Record
CVE-2021-3990- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N - CVSS 3.0
- 6.5 Medium
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:L - CVSS 2.0
- 4.3 Medium
AV:N/AC:M/Au:N/C:P/I:N/A:N - Weakness
- CWE-338
- Updated
- 2026-11-02
OSV
showdoc is vulnerable to Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)
- Record
CVE-2021-3990- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N - Updated
- 2026-11-02
OSVGHSA-vrgh-5w3c-ggf8
showdoc is vulnerable to Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)
showdoc is vulnerable to Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG).
- Record
GHSA-vrgh-5w3c-ggf8- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N - Weakness
- CWE-338
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
showdoc/showdocPackagist |
before 2.9.13 | 2.9.13 |
showdoc/showdocPackagist |
before 2.9.13, plus listed versions v1.0.0v1.0.1v1.0.2v1.0.3v1.0.4 Show 45 moreShow lessv1.0.5v1.1.0v1.1.1v1.1.3v1.1.4v1.1.5v1.2.0v1.2.1v1.2.2v1.2.3v1.2.4v1.2.5v1.2.6v1.3.0v1.3.1v1.3.3v1.3.4v1.3.5v1.3.6v1.3.7v1.3.8v1.4.0v1.4.1v1.4.2v1.4.3v1.4.4v1.4.5v1.4.6v1.4.7v1.5.0v1.5.1v1.5.2v1.5.3v1.6.0v1.6.1v1.6.2v1.7.0v1.7.1v1.7.2v1.8.0v1.8.1v1.8.2v1.8.3v1.8.4v1.8.5 |
2.9.13 |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-3990 is a medium vulnerability (CVSS 6.5) in Showdoc, published December 1, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.89%, the 59th percentile. Fixed in showdoc/showdoc 2.9.13.
References
Left out here: 80 versions. The JSON record has them.