Analysis of spam and virus filter logs showed no evidence of the exploit being used in the wild by malicious actors.
Proton Mail XSS Vulnerability: A Deep Dive into the 2022 Exploit Proton Exploit
The attack required a specific sequence of actions to succeed, which limited its real-world viability: Analysis of spam and virus filter logs showed
The Sonar Research team identified the vulnerability during a routine audit of Proton's open-source repositories. The issue stemmed from how the web application handled user-controlled HTML. While senders need the ability to style messages, failing to properly sanitize certain tags can allow malicious tags to execute in a reader's browser. How the Exploit Worked While senders need the ability to style messages,
Add details about other recent fixes (like the patch). Include SEO keywords tailored for cybersecurity audiences. Proton Mail's responsible vulnerability disclosure policy
If successful, the script would run in the victim's session, allowing the attacker to "see" what the user sees—effectively stealing the decrypted content of their inbox. Proton's Response and Resolution