serverless-dns is a RethinkDNS resolver that deploys to Cloudflare Workers, Deno Deploy, Fastly, and Fly.io. Versions through abd including 0.1.30 have a vulnerability where the pr.yml GitHub Action interpolates in an unsafe manner untrusted input, specifically the github.event.pullrequest.head.repo.cloneurl and github.headref, to a command in the runner. Due to the action using the pullrequesttarget trigger it has permissive permissions by default. An unauthorized attacker can exploit this vulnerability to push arbitrary data to the repository. The subsequent impact on the end-user is executing the attackers' code when running serverless-dns. This is fixed in commit c5537dd, and expected to be released in 0.1.31.