W3C publishes draft threat model to guide security reviews of web standards

The W3C Security Interest Group has published the first draft of Threat Model for the Web, a document that describes the security assumptions, threat landscape, and protection mechanisms that shape the modern web platform. The draft is intended to serve as a reference for security reviews of existing and future web standards.

According to W3C, the document outlines both the broader threat model for the web and the web security model that underpins browsers and web technologies. It also identifies security goals that may not yet be fully realised across the web platform but should still be considered when reviewing proposed technical specifications.

The draft starts from the premise that web browsers occupy a unique position in the digital ecosystem. Browsers routinely execute code and process content from untrusted sources across the internet while also protecting users, devices, and sensitive information. As a result, web security relies heavily on concepts such as origin-based isolation, trust boundaries, and the separation of content from different websites.

The document describes the components of a web browser, the assets that require protection, potential threat sources, and the security features designed to mitigate risks. It is intended to help standards developers assess how proposed technologies could affect confidentiality, integrity, privacy, and the overall security of the web ecosystem.

W3C emphasises that the document is informative rather than normative. It is not expected to become a formal W3C Recommendation and does not create technical requirements. Instead, it provides a shared analytical framework that can be used when designing and reviewing web standards.

The publication follows broader efforts within W3C to integrate threat modelling into standards development.