handlebars security vulnerability - npm won't install

[birdsarah]

On running npm install --no-save

I get the response

> bokehjs@1.1.0-dev8 prepare /home/bird/Dev/bokeh/bokeh/bokehjs
> node ./prepare.js

audited 738 packages in 1.96s
found 1 high severity vulnerability
  run `npm audit fix` to fix them, or `npm audit` for details

Results of npm audit

                                                                    
                       === npm audit security report ===                        
                                                                                
# Run  npm update handlebars --depth 2  to resolve 1 vulnerability
┌───────────────┬──────────────────────────────────────────────────────────────┐
│ High          │ Prototype Pollution                                          │
├───────────────┼──────────────────────────────────────────────────────────────┤
│ Package       │ handlebars                                                   │
├───────────────┼──────────────────────────────────────────────────────────────┤
│ Dependency of │ istanbul [dev]                                               │
├───────────────┼──────────────────────────────────────────────────────────────┤
│ Path          │ istanbul > handlebars                                        │
├───────────────┼──────────────────────────────────────────────────────────────┤
│ More info     │ https://npmjs.com/advisories/755                             │
└───────────────┴──────────────────────────────────────────────────────────────┘


found 1 high severity vulnerability in 738 scanned packages
  run `npm audit fix` to fix 1 of them.