Stored XSS via File Upload in star7th/showdoc


Reported on

Mar 14th 2022


Stored XSS via uploading file in .m3u8a format.

Proof of Concept



Steps to Reproduce

1.Login into
2.Navigate to file library (
3.In the File Library page, click the Upload button and choose the poc.m3u8a file.
4.After uploading the file, click on the check button to open that file in a new tab.

XSS will trigger when the attachment is opened in a new tab.



An attacker can perform social engineering on users by redirecting them from a real website to a fake one. a hacker can steal their cookies etc.

We are processing your report and will contact the star7th/showdoc team within 24 hours. 2 months ago
Ajaysen R submitted a
2 months ago
star7th validated this vulnerability 2 months ago
Ajaysen R has been awarded the disclosure bounty
The fix bounty is now up for grabs
star7th confirmed that a fix has been merged on d1c9ed 2 months ago
Ajaysen R has been awarded the fix bounty
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