
Telegram Desktop XSS Flaw Exposed Chat Exports to Hidden JavaScript Attacks
In June 2026, security researchers ExPatch discovered a critical cross-site scripting (XSS) vulnerability in Telegram Desktop's HTML export feature that allowed malicious bots to embed hidden JavaScript code in chat messages. The flaw affected versions 4.15.1 through 6.9.3, spanning over two years from March 2024 to July 2026. Attackers could exploit this by creating bot messages with script tags in button text, which would execute when users opened exported HTML files in browsers, potentially exfiltrating entire chat histories to attacker-controlled servers or manipulating displayed content. This incident highlights the growing risk of supply chain vulnerabilities in popular communication platforms and the delayed disclosure challenges facing the cybersecurity community. As organizations increasingly rely on messaging platforms for business communications and data export features for compliance, such vulnerabilities expose sensitive corporate communications to potential theft and manipulation.
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