In versions >= 2.82.0, < 2.91.0, if the HTML backend was explicitly configured for rendering (rendering option by default deactivated), then the Playwright-based rendering feature could allow JavaScript execution and unrestricted network access when processing untrusted HTML documents. An attacker could craft malicious HTML that executes arbitrary JavaScript in the rendering context or makes unauthorized network requests to internal services, potentially leading to SSRF attacks, data exfiltration, or remote code execution in the rendering environment.

Fixed in version 2.91.0. The rendering context now explicitly disables JavaScript execution (java script enabled=False) and implements network isolation controls. When enable remote fetch is disabled, the browser operates in offline mode, preventing all network requests.

Refrain from using render page=True when processing untrusted HTML documents.