CVE-2021-43861

Name: CVE-2021-43861
Creator: NVD / NIST
Published: 2021-12-30T14:15:07.547+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.4/10EPSS 0.91%

Last modified Jun 17, 2026

CVE-2021-43861 is a medium-severity vulnerability rated 5.4/10 on the CVSS scale. Mermaid is a Javascript based diagramming and charting tool that uses Markdown-inspired text definitions and a renderer to create and modify complex diagrams. Prior to version 8.13.8, malicious diagrams can run javascript code at diagram readers' machines. EPSS estimates a 0.91% chance of exploitation in the next 30 days.

Description

Mermaid is a Javascript based diagramming and charting tool that uses Markdown-inspired text definitions and a renderer to create and modify complex diagrams. Prior to version 8.13.8, malicious diagrams can run javascript code at diagram readers' machines. Users should upgrade to version 8.13.8 to receive a patch. There are no known workarounds aside from upgrading.

Metrics

CVSS 3.1

5.4/10

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

EPSS Probability

0.91%

55.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Mermaid Project	Mermaid	< 8.13.8

References

https://github.com/mermaid-js/mermaid/commit/066b7a0d0bda274d94a2f2d21e4323dab5776d83Patch, Third Party Advisory
https://github.com/mermaid-js/mermaid/releases/tag/8.13.8Release Notes, Third Party Advisory
https://github.com/mermaid-js/mermaid/security/advisories/GHSA-p3rp-vmj9-gv6vThird Party Advisory
https://github.com/mermaid-js/mermaid/commit/066b7a0d0bda274d94a2f2d21e4323dab5776d83Patch, Third Party Advisory
https://github.com/mermaid-js/mermaid/releases/tag/8.13.8Release Notes, Third Party Advisory
https://github.com/mermaid-js/mermaid/security/advisories/GHSA-p3rp-vmj9-gv6vThird Party Advisory

Timeline

Published: Dec 30, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-43861?

How severe is CVE-2021-43861?

CVE-2021-43861 has a CVSS score of 5.4/10 (MEDIUM severity). The EPSS model estimates a 0.91% probability of exploitation in the next 30 days.

How do I fix CVE-2021-43861?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-43861?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST