How severe is CVE-2021-26608?

CVE-2021-26608 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-26608 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (44th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-26608?

CVE-2021-26608 primarily affects Handysoft Hshell. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-26608?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-26608 published?

CVE-2021-26608 was published on 2021-09-09 and last updated on 2026-06-17.

CVE-2021-26608

CVE-2021-26608 is a high-severity vulnerability in Handysoft Hshell with a CVSS 3.x base score of 8.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-345.

Key facts

Severity: High (CVSS 3.x base score 8.8)
CVSS v2: 7.5
EPSS exploit prediction: 1% (44th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-345
Affected product: Handysoft Hshell
Published: 2021-09-09
Last modified: 2026-06-17

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.

Frequently asked questions

What is 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.
How severe is CVE-2021-26608?: CVE-2021-26608 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-26608 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (44th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-26608?: CVE-2021-26608 primarily affects Handysoft Hshell. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-26608?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-26608 published?: CVE-2021-26608 was published on 2021-09-09 and last updated on 2026-06-17.

References

https://www.boho.or.kr/krcert/secNoticeView.do?bulletin_writing_sequence=36239

Affected products (3)

cpe:2.3:a:handysoft:hshell:1.7.4.5:*:*:*:*:*:*:*
cpe:2.3:a:handysoft:hshell:2.0.3.5:*:*:*:*:*:*:*
cpe:2.3:a:handysoft:hshell:4.0.1.6:*:*:*:*:*:*:*

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