In most scenarios, the attack only worked if the victim viewed both emails and clicked a specific link in the second one.

When possible, use native desktop or mobile apps which often have different attack surfaces than web-based versions. If you'd like to refine this draft, tell me if you want to:

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

The vulnerability was strictly limited to the web interface; non-web Proton Mail apps (iOS/Android) were never affected. Protecting Your Data

After researchers disclosed the bug in June 2022, Proton developed and deployed a fix by early July 2022.

Analysis of spam and virus filter logs showed no evidence of the exploit being used in the wild by malicious actors.

Add details about other recent fixes (like the patch). Include SEO keywords tailored for cybersecurity audiences. Proton Mail's responsible vulnerability disclosure policy

In June 2022, security researchers from SonarSource discovered a critical Cross-Site Scripting (XSS) vulnerability in the open-source code of Proton Mail. This flaw could have allowed attackers to bypass end-to-end encryption to steal decrypted emails and impersonate victims. The Discovery