Rehype-raw is a Markdown processing step that reparses raw HTML into real elements instead of leaving it as escaped text. It is useful for formatting, but it also reintroduces executable markup risk unless a sanitizer runs after parsing and attributes are tightly controlled.
Expanded Definition
Rehype-raw is the step in a Markdown rendering pipeline that turns raw HTML embedded in Markdown back into parsed HTML elements. In practice, that means content that would otherwise be displayed as literal text can become active markup with browser interpretation, which is why the term matters in security-sensitive content workflows. The concept sits at the boundary between formatting convenience and trust enforcement, especially in pipelines that accept user-generated or partially trusted content.
Definitions vary across vendors and framework ecosystems, but the operational meaning is consistent: raw HTML is no longer inert once it is reparsed. That distinction is important in NHI security documentation because markdown-driven portals, policy sites, and internal knowledge bases often mix authored text with embedded components, links, and snippets. When used without a sanitizer or attribute allowlist, rehype-raw can reopen the door to script injection, event-handler abuse, or unsafe inline content. For governance teams, this is less about syntax and more about whether the content pipeline preserves security intent after transformation. The most common misapplication is enabling raw HTML for convenience while assuming the Markdown layer itself still provides protection, which occurs when sanitization is omitted after parsing.
For baseline identity and access context, see the NIST Cybersecurity Framework 2.0, which frames secure processing and control enforcement as part of resilience.
Examples and Use Cases
Implementing rehype-raw rigorously often introduces a rendering and review burden, requiring organisations to weigh flexible authoring against the cost of stricter sanitization and content governance.
- A documentation site allows trusted editors to embed tables and callouts in Markdown, then runs a sanitizer after rehype-raw so only approved tags and attributes survive.
- An internal NHI knowledge base accepts contributed articles that include raw HTML snippets, but rejects inline scripts and unsafe links before publication.
- A support portal converts Markdown into HTML for better formatting, yet blocks event handlers and iframes to avoid turning content into an attack surface.
- A security team audits a pipeline after noticing that raw HTML is being rendered directly, then adds a post-parse sanitization step and stricter template controls. The Ultimate Guide to NHIs shows why controls must be explicit when identity-related content is widely distributed.
- A governance workflow permits limited formatting in policy pages, but strips unexpected attributes to keep the rendered output deterministic and reviewable.
For implementation guidance, the NIST Cybersecurity Framework 2.0 remains relevant because content handling is part of a broader protection strategy.
Why It Matters in NHI Security
Rehype-raw matters in NHI security because security teams often publish guidance, runbooks, token-handling instructions, and incident notes through Markdown-based systems. If raw HTML is allowed without a sanitizer, an attacker who can influence content may inject malicious markup into pages that operators trust, which can lead to phishing, credential theft, or session compromise inside an internal control plane. The risk is amplified when identity and access documentation is reused across teams or copied into automation portals.
NHIMG research shows that 79% of organisations have experienced secrets leaks, with 77% of those incidents resulting in tangible damage, a reminder that content pathways can become part of the exposure chain when controls are weak. This is why the Ultimate Guide to NHIs is relevant here: documentation and governance content must be treated as a controlled surface, not a harmless publishing detail. When paired with NIST Cybersecurity Framework 2.0 principles, the operational lesson is clear: parse first, then sanitize, then publish only what has been explicitly permitted. Organisations typically encounter the consequences only after a malicious snippet is rendered in a trusted portal, at which point rehype-raw becomes operationally unavoidable to address.
Standards & Framework Alignment
This section maps relevant standards and security frameworks to the operational risks and controls described in this guidance.
OWASP Non-Human Identity Top 10 and OWASP Agentic AI Top 10 address the attack and risk surface, while NIST CSF 2.0, NIST AI RMF and NIST Zero Trust (SP 800-207) set the governance and control requirements practitioners need to meet.
| Framework | Control / Reference | Relevance |
|---|---|---|
| OWASP Non-Human Identity Top 10 | NHI-02 | Unsafe content parsing can expose credentials and trusted surfaces to injection paths. |
| NIST CSF 2.0 | PR.DS | Raw HTML handling affects data integrity and protection of trusted content workflows. |
| NIST AI RMF | Prompt and content pipelines must be governed to reduce unsafe transformation risk. | |
| NIST Zero Trust (SP 800-207) | Trusted rendering paths should not assume content is safe without explicit verification. | |
| OWASP Agentic AI Top 10 | Agentic content generation can introduce unsafe markup that must be controlled downstream. |
Treat any transformation that enables executable markup as a managed risk with validation gates.
Related resources from NHI Mgmt Group
Deepen Your Knowledge
Reviewed and updated by the NHIMG editorial team on August 21, 2026.
NHI Mgmt Group — the #1 independent authority on Non-Human Identity, IAM, and Agentic AI security. nhimg.org
