@digitalocean/do-markdownit has Type Confusion vulnerability

Overview A type confusion issue exists in the @digitalocean/do-markdownit package. In the callout and fenceenvironment plugins, the allowedClasses and allowedEnvironments options are expected to be arrays of strings. If these options are provided as a single string, the code applies .includes...

CVE-2025-59717

In the @digitalocean/do-markdownit package through 1.16.1 in npm, the callout and fenceenvironment plugins perform .includes substring matching if allowedClasses or allowedEnvironments is a string instead of an array...