As of today Heroku announced that a high severity remote Denial of Service (DoS) Constant Hashtable Seeds vulnerability in Node.js versions 4.x through 8.x has been patched in the following versions: 4.8.4, 6.11.1, 7.10.1, 8.1.4.
Slack-rss doesn't specify a version and is running v5.11.1.
You could specify a version like this https://devcenter.heroku.com/articles/nodejs-support#specifying-a-node-js-version
As of today Heroku announced that a high severity remote Denial of Service (DoS) Constant Hashtable Seeds vulnerability in Node.js versions 4.x through 8.x has been patched in the following versions: 4.8.4, 6.11.1, 7.10.1, 8.1.4.
Slack-rss doesn't specify a version and is running v5.11.1.
You could specify a version like this https://devcenter.heroku.com/articles/nodejs-support#specifying-a-node-js-version