Is DraftSharks Sync safe?

Clean risk

DraftSharks Sync embeds a Yahoo OAuth client credential and uses it when exchanging Yahoo authorization tokens.

DraftSharks Sync connects to Yahoo Fantasy Sports by sending OAuth authorization and refresh-token requests to Yahoo's login API. The shipped extension includes the same Basic OAuth client credential in those token requests, so the credential is present in the extension code as well as in requests to Yahoo.

DraftSharksv4.20Firefox Add-ons
2Risk
Who publishes it

DraftSharks - no other listings under this identity, 15 shared hostnames

What this publisher told the store about itself, and the other listings that told it the same thing.

Publisher
DraftSharks

Shared hosts - 15 hostnames

Hostnames hardcoded in this extension that few other listings call. That can mean one operator behind both, and it can equally mean a small shared vendor, so it is context rather than a conclusion. Hosts that many listings call are left out: they are services, not connections.

api.fantasy.nfl.com
Also called by 2 other listings
api2.fantasy.nfl.com
Also called by 2 other listings
beta.draftsharks.com
Also called by 2 other listings
draftsharks.com
Also called by 2 other listings, including DraftSharks Sync
draftsharks.devo
Also called by 2 other listings
draftsharks.local
Also called by 2 other listings, including DraftSharks Sync
feature.draftsharks.com
Also called by 2 other listings, including DraftSharks Sync
lm-api-communication.fantasy.espn.com
Also called by 2 other listings, including DraftSharks Sync
www43.myfantasyleague.com
Also called by 2 other listings
www47.myfantasyleague.com
Also called by 2 other listings
fleaflicker.com
Also called by 3 other listings
rtsports.com
Also called by 3 other listings, including Draft Hero Live Sync for Fantasy Football
api.underdogsports.com
Also called by 4 other listings
myffpc.com
Also called by 4 other listings, including Draft Hero Live Sync for Fantasy Football
underdogsports.com
Also called by 5 other listings, including SharpSports

AI-generated. Findings may contain errors. Those marked Verified have been manually reviewed.

Publishers can request a review.

What it can do

Permissions this extension asks for, as declared in version 4.20. Asking for a permission is not a finding on its own - it is what the extension can do if it chooses to.

  • Read and change your data on draftsharks.com

    https://*.draftsharks.com/*

  • Read and change your data on draftsharks.local

    https://draftsharks.local/*

  • Read and change your data on draftsharks.devo

    https://*.draftsharks.devo/*

  • Read and change your data on football.fantasysports.yahoo.com

    https://football.fantasysports.yahoo.com/ and 1 more

  • Read and change your data on fantasysports.yahooapis.com

    https://fantasysports.yahooapis.com/ and 3 more

  • Read and change your data on api.login.yahoo.com

    https://api.login.yahoo.com/oauth2/ and 1 more

  • Read and change your data on login.yahoo.com

    https://login.yahoo.com/manage_account*

  • Read and change your data on pub-api-rw.fantasysports.yahoo.com

    https://pub-api-rw.fantasysports.yahoo.com/*

  • Read and change your data on pub-api-ro.fantasysports.yahoo.com

    https://pub-api-ro.fantasysports.yahoo.com/*

  • Read and change your data on espn.com

    http://espn.com/

  • Read and change your data on fantasy.espn.com

    https://fantasy.espn.com/ and 3 more

  • Read and change your data on cbssports.com

    *://cbssports.com/ and 3 more

  • Read and change your data on www.cbssports.com

    https://www.cbssports.com/ and 11 more

  • Read and change your data on football.cbssports.com

    https://*.football.cbssports.com/api/* and 3 more

  • Read and change your data on myfantasyleague.com

    *://myfantasyleague.com/ and 1 more

  • Read and change your data on rtsports.com

    *://*.rtsports.com/

  • Read and change your data on myffpc.com

    *://myffpc.com/ and 3 more

  • Read and change your data on fantrax.com

    *://*.fantrax.com/ and 1 more

  • Read and change your data on nfl.com

    *://*.nfl.com/

  • Read and change your data on api.fantasy.nfl.com

    *://api.fantasy.nfl.com/ and 1 more

  • Read and change your data on api2.fantasy.nfl.com

    *://api2.fantasy.nfl.com/ and 1 more

  • Read and change your data on fleaflicker.com

    https://*.fleaflicker.com/ and 1 more

  • Read and change your data on sleeper.app

    https://sleeper.app/ and 3 more

  • Read and change your data on sleeper.com

    https://sleeper.com/ and 11 more

  • Read and change your data on underdogfantasy.com

    http://underdogfantasy.com/ and 7 more

  • Read and change your data on underdogsports.com

    http://underdogsports.com/ and 7 more

  • Read and change cookies, including the ones that keep you signed in

    cookies

  • See the address and title of every tab you have open

    tabs

  • Run its own code inside the pages you visit

    scripting

  • Store data in your browser

    storage

  • Watch every request your browser makes

    webRequest

Where it sends data

Destinations our analysis observed DraftSharks Sync contacting. Sending data somewhere is not a finding on its own - an extension that syncs your settings has to talk to its own server - but it is where your data can go, and who else it goes to.

  • api.login.yahoo.com

    DraftSharks Sync sends data to api.login.yahoo.com. One other extension we have analysed sends data here.

Updated 30 September 2026amo-2663040