CVE-2021-47970

HIGH
Published May 16, 2026 Modified May 18, 2026 CWE-789

Description

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.

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CVSS v3.1 Score

7.5
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS — Exploit Prediction

0.0005
Probability of exploitation
0.17%
Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-789 CWE-789

References

Frequently Asked Questions

What is CVE-2021-47970? +
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. It has a CVSS v3.1 base score of 7.5 (HIGH).
How severe is CVE-2021-47970? +
CVE-2021-47970 has a CVSS v3.1 score of 7.5 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0005, placing it in the 0th percentile for exploitation probability.
How do I check if I'm vulnerable to CVE-2021-47970? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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