XSS in Mermaid-Js Mermaid

CVE-2025-54880

Mermaid is a JavaScript based diagramming and charting tool that uses Markdown-inspired text definitions and a renderer to create and modify complex diagrams. In the default configuration of mermaid 11.9.0 and earlier, user supplied input for architecture diagram icons is passed to the d3 html() method, creating a sink for cross site scripting. This vulnerability is fixed in 11.10.0.

Vulnerability class: XSS (Cross-Site Scripting)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.004 (35.3th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 35th percentile — 35.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-54880: held from 0.004 to 0.004.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: +0.000

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2025-54880?
CVE-2025-54880 is a medium-severity vulnerability in Mermaid-Js Mermaid, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2025-08-19.
How severe is CVE-2025-54880?
Medium severity. CVSS v3 base score is 6.1 out of 10.
Is CVE-2025-54880 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.