How severe is CVE-2021-47821?

CVE-2021-47821 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2021-47821 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (29th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2021-47821?

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-2021-47821 have an EU (EUVD) identifier?

Yes. CVE-2021-47821 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-2891.

When was CVE-2021-47821 published?

CVE-2021-47821 was published on 2026-01-16 and last updated on 2026-06-17.

CVE-2021-47821

CVE-2021-47821 is a high-severity vulnerability with a CVSS 3.x base score of 7.5. 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-1284.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v4: 4.6
EPSS exploit prediction: 0% (29th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-2891
Weakness: CWE-1284
Published: 2026-01-16
Last modified: 2026-06-17

Description

RarmaRadio 2.72.8 contains a denial of service vulnerability that allows attackers to crash the application by overflowing network configuration fields with large character buffers. Attackers can generate a 100,000 character buffer and paste it into multiple network settings fields to trigger application instability and potential crash.

Frequently asked questions

What is CVE-2021-47821?: RarmaRadio 2.72.8 contains a denial of service vulnerability that allows attackers to crash the application by overflowing network configuration fields with large character buffers. Attackers can generate a 100,000 character buffer and paste it into multiple network settings fields to trigger application instability and potential crash.
How severe is CVE-2021-47821?: CVE-2021-47821 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2021-47821 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (29th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2021-47821?: 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-2021-47821 have an EU (EUVD) identifier?: Yes. CVE-2021-47821 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-2891.
When was CVE-2021-47821 published?: CVE-2021-47821 was published on 2026-01-16 and last updated on 2026-06-17.

References

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