How severe is CVE-2021-47816?

CVE-2021-47816 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-47816 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (73rd percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2021-47816?

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.

Does CVE-2021-47816 have an EU (EUVD) identifier?

Yes. CVE-2021-47816 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-2902.

When was CVE-2021-47816 published?

CVE-2021-47816 was published on 2026-01-16 and last updated on 2026-06-17.

CVE-2021-47816

CVE-2021-47816 is a high-severity vulnerability 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-78.

Key facts

Severity: High (CVSS 3.x base score 8.8)
CVSS v4: 5.3
EPSS exploit prediction: 2% (73rd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-2902
Weakness: CWE-78
Published: 2026-01-16
Last modified: 2026-06-17

Description

Thecus N4800Eco NAS Server Control Panel contains a command injection vulnerability that allows authenticated attackers to execute arbitrary system commands through user management endpoints. Attackers can inject commands via username and batch user creation parameters to execute shell commands with administrative privileges.

Frequently asked questions

What is CVE-2021-47816?: Thecus N4800Eco NAS Server Control Panel contains a command injection vulnerability that allows authenticated attackers to execute arbitrary system commands through user management endpoints. Attackers can inject commands via username and batch user creation parameters to execute shell commands with administrative privileges.
How severe is CVE-2021-47816?: CVE-2021-47816 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-47816 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (73rd percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2021-47816?: 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.
Does CVE-2021-47816 have an EU (EUVD) identifier?: Yes. CVE-2021-47816 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-2902.
When was CVE-2021-47816 published?: CVE-2021-47816 was published on 2026-01-16 and last updated on 2026-06-17.

References

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