What is the CVSS score of CVE-2021-47970?

CVE-2021-47970 has a CVSS 4.0 base score of 8.7 (High). CVSS vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N. EPSS exploitation probability: 0.0%.

Is there a public PoC exploit available for CVE-2021-47970?

Yes, a public proof-of-concept exploit is available for CVE-2021-47970. Prioritise patching immediately. EPSS: 0.0%.

Macaron Notes Gear Notebook CVE-2021-47970

EUVD-2021-34829 HIGH

Memory Allocation with Excessive Size Value (CWE-789)

2026-05-16 VulnCheck

GHSA-4439-4hh6-5j2w

Denial Of Service Macaron Notes Gear Notebook

8.7

CVSS 4.0 · NVD

View

Vulnerability Assessment

Weakness	CWE CWE-789 ASVS 5.0 V15 - Secure Coding and Architecture Memory allocation limits
Impact	CVSS score of 8.7 (HIGH). Attack characteristics: network attack vector, low complexity, no privileges required, no user interaction not required. Public proof-of-concept exploit code is available. EPSS exploitation probability: 0.04%.
Exploit ScenarioDerived	This vulnerability can be exploited remotely over the network. Successful exploitation could compromise the high-severity affected system.

This Week Schedule remediation this week. Why: HIGH severity (CVSS 7.0-8.9).

No patch listed yet 0.0% exploitation probability (EPSS)

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AnalysisAI

Macaron Notes 5.5 contains a denial of service vulnerability that allows attackers to crash the application by creating notes with excessively long character strings. Rated high severity (CVSS 8.7), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.

RemediationAI

No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Apply vendor patches when available. Implement network segmentation and monitoring as interim mitigations.

Affected VersionsENISA

Macaron Notes Gear Notebook 5.5

Affected Packages

euvd macaron_notes_gear_notebook no fix

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 1 package in euvd

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

This vulnerability is classified under CWE-789. Macaron Notes 5.5 contains a denial of service vulnerability that allows attackers to crash the application by creating notes with excessively long character strings. Attackers can generate a payload containing 350000 repeated characters and paste it into a note field to trigger application crash and stop functionality. Affected products include: Macaron-Notes-Great-Notebook Macaron Notes Gear Notebook.

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Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

NVD PRIMARY 8.7 HIGH

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector

Network

Attack Complexity

Low

Attack Requirements

None

Privileges Required

None

User Interaction

None

Vulnerable system: Confidentiality

None

Vulnerable system: Integrity

None

Vulnerable system: Availability

High

Subsequent system: Confidentiality

None

Subsequent system: Integrity

None

Subsequent system: Availability

None

Lifecycle Timeline

CVSS changed

May 16, 2026 - 16:22 NVD

7.5 (HIGH) 8.7 (HIGH)

CVE Published

May 16, 2026 - 15:26 cve.org

HIGH 8.7

DescriptionCVE.org

Macaron Notes 5.5 contains a denial of service vulnerability that allows attackers to crash the application by creating notes with excessively long character strings. Attackers can generate a payload containing 350000 repeated characters and paste it into a note field to trigger application crash and stop functionality.

Threat Intelligence Overview

EPSS Score

0.0%

Top 88% exploitable

Exploit

POC

Public exploit code exists

Social Media

Sightings

Data Quality

6 sources

Confidence: High

EUVD

NVD

CVE.org

EPSS

Vulnrichment CIRCL

Exploit-DB

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue

Severity HIGH

CISA KEV No

Public POC Yes

EPSS 0.0%

Patch available No

Active threat No

Deciding rule

HIGH severity (CVSS 7.0-8.9)

What every action level means

Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.

Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.

This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.

This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.

Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.