CVE-2021-43861: high-severity vulnerability in mermaid-js mermaid
Incorrect sanitisation function leads to `XSS`
Published · Updated
E-mail alert when it lands in KEV, gets a public PoC or its score goes up.
21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 7.2epss 0.9%
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.
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
Affected products
mermaid-js · mermaidRelated CVEs — mermaid-js mermaid
In the same product, most dangerous first.
CVE-2022-31108MEDIUMArbitrary `CSS` injection into the generated graph affecting the container HTML in mermaid.jsEPSS 0.9%CVE-2025-54881MEDIUMMermaid improperly sanitizes of sequence diagram labels leading to XSSEPSS 0.9%CVE-2026-50159MEDIUMMermaid allows CSS injection applying to sibling elements of the diagramEPSS 0.6%CVE-2026-71436MEDIUMMermaid XY Charts are vulnerable to an infinite loop DoSEPSS 0.6%CVE-2026-71439MEDIUMMermaid radar diagrams are vulnerable to DoSEPSS 0.5%CVE-2026-71437MEDIUMMermaid Architecture diagrams are vulnerable to prototype pollutionEPSS 0.5%