How to verify if the submodule hash is pushed to the remote?

I've a monorepo with many submodules,everytime a PR is raised on my monrepo to update hashes of the submodule, i need to run a jenkins job to see if the hashes in the source branch of PR are in remote of the submdule.

This to avoid failure while building sub modules(because sometimes people fail to commit their changes to remote, but still update hash)

Quickest way to do this is to run some commands on parallel
what will be those commands?

Thank you in advance

git clone <url> --branch $PR_SOURCE_BRANCH --single-branch <somefoldername>
after this??

As suggested by the gentlemen @joanis in the comments, i shifted my focus from git commands to bitbucket rest APIs, and response is quick

node {
    //SCM checkout
    stage('Perform Hash check') {
        cleanWs()
        sh "git clone <url> --branch $PR_SOURCE_BRANCH --single-branch <somefoldername>"
        dir(<somefoldername>) {
            def map = [:]
            def commitList = sh( script:"(git submodule status | awk '{ print \$1 \" \" \$2 }')",returnStdout: true).replace("-","").split("\n")
            commitList.each {
                map[it.split(" ")[0].trim()] = it.split(" ")[1].trim()
            }
            map.each { commitid, reponame ->
                def url = "https://api.bitbucket.org/2.0/repositories/reposlug/$reponame/commits/$commitid"
                final def (String response, int code) = sh(script: "curl -s -w '\\n%{response_code}' -u username:app-password $url", returnStdout: true).trim().tokenize("\n")
                if (code != 200) {
                    error()
                }                
            }
        }
        
    }
}

Solution

Promoting my comment to an answer, since the solution worked.

Doing some research, I could not find a Git command to do what you want, but if your Git server includes a repo browsing interface, like GitHub does, trying to fetch

https://github.com/<space>/<repo>/commit/<hash>

will give you a 200 on success, 404 on failure and thus tell you if the commit exists.

Since this page only points to an index of the files in the commit, but does not include any actual contents, this should be a very efficient check.