Other nomination

XSS in GMAIL Dynamic Email

asdqw3 · Medium · 7 July 2026

Gmail's AMP for Email sanitizer could be escaped from inside a style amp-custom block: the parser acted on an unterminated closing style tag and auto-generated closing tags, letting injected markup break into the document body. Only a meta refresh survived the tag filter, navigating the mail view to a data URL; Gmail's CSP blocked script execution. Google paid a 6,000 dollar bounty.

Record

Researcher

asdqw3

Published by

Medium

Date

7 July 2026

In the archive

• Nominated for the 2023 Top 10 Web Hacking Techniques

Tags

• xss
• sanitizer-bypass
• email
• css
• parser-differential
• filter-bypass
• csp
• bug-bounty
• owasp-a03-2021
• owasp-a05-2021

This page is the archive's own catalogue record. The research is the work of asdqw3, first published at the original source. Preserved copies are kept so the citation survives its host.