Parameter Labs Discloses Critical Chatgpt Sandbox Vulnerability
On October 31, 2026, researchers at Parameter Labs disclosed a vulnerability where an insecure postMessage handler and innerHTML usage allowed attackers to bypass CSP restrictions and execute code on the ChatGPT main page.
OpenAI's use of innerHTML in a product handling untrusted AI output is a surprising oversight. This patch fixes a specific hole, but the underlying complexity of iframe-based sandboxing remains a fragile security layer for chat interfaces.
Expect a wave of similar 'sandbox escape' disclosures as researchers pivot from prompt injection to traditional DOM vulnerabilities in AI web apps.









