Do the math: How we took over ChatGPT accounts
Parameter Labs describes a chain that turned a public ChatGPT share link into JavaScript running as chatgpt.com in the victim's session. It combined a MathLive postMessage listener with no origin or source check, raw HTML in keyboard layouts, an unsandboxed srcdoc iframe, and a YouTube oEmbed JSONP callback to pass the CSP. The code read private conversations through backend APIs. OpenAI fixed it on 26 October 2026 and rated it P1.
AppSecΒ· Added 1 Nov 2026, published 31 Oct 2026






















