# CVE-2021-3689

## Summary

- **CVE ID:** CVE-2021-3689
- **Severity:** HIGH
- **CVSS Score:** 8.1 (CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H)
- **CWE:** CWE-1241
- **Published:** Aug 10, 2021
- **Last Modified:** Mar 13, 2026

## Description

yii2 is vulnerable to Use of Predictable Algorithm in Random Number Generator

## Affected Products

- yiisoft — yiisoft/yii2 (unspecified)

## References

- [CNA](https://huntr.dev/bounties/50aad1d4-eb00-4573-b8a4-dbe38e2c229f)
- [CNA](https://github.com/yiisoft/yii2/commit/13f27e4d920a05d53236139e8b07007acd046a46)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.45%
- **EPSS Percentile:** 63.2

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-11._