# CVE-2021-26608

## Summary

- **CVE ID:** CVE-2021-26608
- **Severity:** HIGH
- **CVSS Score:** 8.8 (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H)
- **CWE:** CWE-353
- **Published:** Sep 9, 2021
- **Last Modified:** Mar 13, 2026

## Description

An arbitrary file download and execution vulnerability was found in the HShell.dll of handysoft Co., Ltd groupware ActiveX module. This issue is due to missing support for integrity check of download URL or downloaded file hash.

## Affected Products

- handysoft — HShell.dll (1.7.4.5)
- handysoft — HShell.dll (2.0.3.5)
- handysoft — HShell.dll (4.0.1.6)

## References

- [CNA](https://www.boho.or.kr/krcert/secNoticeView.do?bulletin_writing_sequence=36239)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.23%
- **EPSS Percentile:** 45.9

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-18._