Mermaid radar diagrams allow arbitrary large values for ticks, which can cause high CPU usage, freezing the webpage/JavaScript process for long periods of time, until the process is eventually killed due to OOM/running out of memory.

radar-beta
 axis a, b
 curve c {1, 1}
 ticks 1000000000

Has the problem been patched? What versions should users upgrade to?

This problem has been patched by https://github.com/mermaid-js/mermaid/commit/59b22fad2b3bb04f87a476c84a8a2b24679e607e, which was released in Mermaid v11.16.1

Is there a way for users to fix or remediate the vulnerability without upgrading?

There are no known workarounds without updating to a patched version of mermaid.

Are there any links users can visit to find out more?