# Introducing OPSWAT File Structure Validation > Source: > Published: 2026-08-28 07:00:00+00:00 On August 28, 2026, OPSWAT is releasing File Structure Validation in MetaDefender Core™. [File Structure Validation](https://www.opswat.com/technologies/file-structure-validation) is a new technology that validates file format integrity, extracts embedded objects, and routes each component to the appropriate security engine. It is designed to close a structural enforcement gap that existing tools were not designed to fill: coverage across complex file formats, at the earliest point in the workflow, without modifying the files it inspects. ## What File Structure Validation Does ### Validate File Structure Validation checks every file against its format specification across 160+ file types, including database files, GIS files, AI model formats, and other complex formats that AV and traditional file sanitization cannot fully process. This includes detection of polyglot files: files that are simultaneously valid under two format specifications; a technique used to bypass file type checks that conventional tools cannot catch at the surface level. For PDF files, FSV also validates digital signatures and verifies signer certificates against known Certificate Authorities. ### Extract Once a file passes structural validation, FSV breaks it into its discrete components: macros, hyperlinks, embedded executables, metadata, images, and nested files. Each extracted component is classified as a risk object or a regular object. Child files are routed independently through the security workflow rather than assessed as part of the parent file, e.g. attachments or embedded objects buried three layers inside a compound document are evaluated on their own terms, not treated as binary content belonging to the file that contained it. ### Block Blocking rules are configurable by object type and per-file-type condition, giving security teams precise control at the point of entry without blanket policies. In addition to standard file specifications, File Structure Validation also validates files against user-defined schema (supporting XML schema (XSD) in this version). Files with malformed, non-compliant, or anomalous structures are blocked before they reach any downstream engine. Files that fail structural checks are blocked before extraction begins, eliminating processing overhead for structurally invalid files. Only files that passed structural validation proceed to downstream engines. ## Who This Is For File Structure Validation addresses three specific gaps that other tools in the stack were not built to cover: - First, organizations handling database files, GIS files, AI model files, and other complex formats where AV cannot complete structural analysis. - Second, environments where file integrity must be preserved after inspection, including legal, forensic, and compliance-regulated workflows where file reconstruction is not applicable. - Third, security teams that need structural enforcement and object-level routing at the earliest point in the pipeline, before heavy inspection begins. ## What Is Included at Launch - File structure validation across 160+ file types - Polyglot file detection at the structural level - PDF digital signature validation and signer certificate verification - Schema validation against XML and related formats including ZEI, JNLP, TDS, RDF, BML, MPD, and TTML - Configurable blocking rules by object type and JSON path condition, per file type - Configurable object detail exposure, from structural overview to full object-level data including relationships and offsets - Non-modifying inspection: the original SHA256 hash is preserved after processing ## Get Started File Structure Validation is available natively in MetaDefender Core™. It is a layer in the existing workflow configuration, not a separate product to integrate. To see File Structure Validation in action or to discuss how it fits into your existing deployment, refer to the [official documentation](https://www.opswat.com/docs/mdcore/file-structure-validation) or contact the Support Team.