What is CVE-2021-26608?

CVE-2021-26608 is a high-severity vulnerability in Handysoft Hshell, classified under CWE-353. CVSS score: 8.8/10. Published 2021-09-09.

How severe is CVE-2021-26608?

High severity. CVSS v3 base score is 8.8 out of 10.

Vulnerability in Handysoft Hshell

CVE-2021-26608

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.

Published 2021-09-09 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.006 (47.3th percentile), scored 2026-10-19.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 47th percentile — 47.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000

Affected products

Handysoft Hshell — versions 1.7.4.5, 2.0.3.5, 4.0.1.6
Handysoft Hshell.dll — versions 1.7.4.5, 2.0.3.5, 4.0.1.6
Microsoft Windows

Weakness classification (CWE)

References

www.boho.or.kr/krcert/secNoticeView.do (Third Party Advisory)

Frequently asked questions

What is CVE-2021-26608?: CVE-2021-26608 is a high-severity vulnerability in Handysoft Hshell, classified under CWE-353. CVSS score: 8.8/10. Published 2021-09-09.
How severe is CVE-2021-26608?: High severity. CVSS v3 base score is 8.8 out of 10.