How severe is CVE-2021-47944?

CVE-2021-47944 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 none, integrity none, and availability high.

Is CVE-2021-47944 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (20th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2021-47944?

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-2021-47944 have an EU (EUVD) identifier?

Yes. CVE-2021-47944 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-34804.

When was CVE-2021-47944 published?

CVE-2021-47944 was published on 2026-05-10 and last updated on 2026-06-17.

CVE-2021-47944

CVE-2021-47944 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-789.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v4: 8.7
EPSS exploit prediction: 0% (20th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2021-34804
Weakness: CWE-789
Published: 2026-05-10
Last modified: 2026-06-17

Description

memono Notepad 4.2 contains a denial of service vulnerability that allows attackers to crash the application by pasting excessively long character buffers into note fields. Attackers can generate a payload containing 350000 repeated characters and paste it twice into a new note to trigger an application crash on iOS devices.

Frequently asked questions

What is CVE-2021-47944?: memono Notepad 4.2 contains a denial of service vulnerability that allows attackers to crash the application by pasting excessively long character buffers into note fields. Attackers can generate a payload containing 350000 repeated characters and paste it twice into a new note to trigger an application crash on iOS devices.
How severe is CVE-2021-47944?: CVE-2021-47944 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 none, integrity none, and availability high.
Is CVE-2021-47944 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (20th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2021-47944?: 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-2021-47944 have an EU (EUVD) identifier?: Yes. CVE-2021-47944 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-34804.
When was CVE-2021-47944 published?: CVE-2021-47944 was published on 2026-05-10 and last updated on 2026-06-17.

References

Other CWE-789 vulnerabilities

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CVE-2026-20048 — High (CVSS 7.7): A vulnerability in the Simple Network Management Protocol (SNMP) subsystem of Cisco Nexus 9000 Series Fabric Switches…
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