CVE-2020-35698: Thinkific Thinkific Online Course Creation Platform 1.0 is affected by: Cross Site Scripting (XSS).

Thinkific Thinkific Online Course Creation Platform 1.0 is affected by: Cross Site Scripting (XSS).

Thinkific Thinkific Online Course Creation Platform 1.0 is affected by: Cross Site Scripting (XSS). The impact is: execute arbitrary code (remote). The component is: Affected Source code of the website CMS which is been used by many to host their online courses using the Thinkific Platform. The attack vector is: To exploit the vulnerability any user has to just visit the link - https://hacktify.thinkific.com/account/billing?success=%E2%80%AA%3Cscript%3Ealert(1)%3C/script%3E. ¶¶ Thinkific is a Website based Learning Platform Product which is used by thousands of users worldwide. There is a Cross Site Scripting (XSS) based vulnerability in the code of the CMS where any attacker can execute a XSS attack. Proof of Concept & Steps to Reproduce: Step1 : Go to Google.com Step 2 : Search for this Dork site:thinkific.com -www Step 3 : You will get a list of websites which are running on the thinkific domains. Step 4 : Create account and signin in any of the website Step 5 : Add this endpoint at the end of the domain and you will see that there is a XSS Alert /account/billing?success=%E2%80%AA<script>alert(1)</script> Step 6 : Choose any domains from google for any website this exploit will

Description from the National Vulnerability Database, published by MITRE

What it means for a small business

If your business uses Thinkific, install the vendor's update. If you're not sure whether you use it, ask whoever manages your computers.

How likely is an attack? The Exploit Prediction Scoring System, run by FIRST (the global association of security response teams), puts the odds of this one being exploited in the next 30 days at 0.52%, higher than 44% of CVEs. That’s low, but low isn’t zero, and the odds jump the day someone publishes an exploit. Scored November 2, 2026, updated daily.

Check your own setup

Website check: reads what your site runs from the outside (WordPress version, plugins it can see, old server software) and matches it against this database.
Server check: what your web server says about itself, and whether that version has known flaws.

Sources

Part of the Huttenlocher Technologies vulnerability database, refreshed twice a day from CISA and the NVD. The title, category and plain-language guidance are ours; check the linked record before acting on a detail. This is general guidance, not a review of your systems.

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