Is Slack Printer safe?

Medium risk

Slack Printer sends Slack page URLs, titles, and browser interest cohort data to slackext.com analytics.

When its popup workflow runs, Slack Printer asks the active Slack tab for the current URL and title, reads the browser interest cohort value if available, and posts those values with a source tag to slackext.com/api/log. The data includes the Slack page URL, page title, tab/app context, and any available FLoC interest cohort value.

hhhustv1.10.0Chrome Web Store
45Risk
Who publishes it

hhhust - 2 other listings from the same operator, 1 of them carrying a finding

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

Publisher
hhhust
Website
slackext.com/printer

Same store account

2 other listings published from this account, 6k+ users between them. 1 of them carries a finding.

Slack Deleter3k+CleanDiscord Batch Deleter3k+Medium

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

Publishers can request a review.

Findings

Slack Printer posts Slack page details to slackext.com analytics

Using Slack Printer's popup on a Slack page collects the current page URL, page title, tab context, and browser interest cohort when Chrome exposes it, then posts those values to slackext.com/api/log as an analytics log request.

Severity
Medium unwanted
Type
Unexpected
CWE
CWE-359
Source
Dynamic sandbox
What actually happens
You did this

The user opens or uses the Slack Printer popup on an active Slack tab.

The extension did this

The extension collects the Slack page URL, page title, tab context, and available browser interest cohort, then posts them to slackext.com analytics.

Captured request
POSThttps://slackext.com/api/log
Fields in the request
  • Slack page URL
    https://example.slack.com/archives/C1234567890

    Shows which Slack page was open when the popup workflow ran.

  • Slack page title
    example - general - Slack

    Adds page context such as the workspace, channel, or conversation title shown by the tab.

  • Active tab context
    slackext-content

    Links the analytics event to the active Slack tab and stored source tag used by the extension workflow.

What it can do

Permissions this extension asks for, as declared in version 1.10.0. 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 slackext.com

    https://slackext.com/*

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

    tabs

  • Store data in your browser

    storage

Where it sends data

Destinations our analysis observed Slack Printer 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.

  • slackext.com

    Slack Printer sends data to slackext.com. One other extension we have analysed sends data here.

Updated 30 September 2026pmoidapkjjlhcdbdjojaekbdlkdjjoab