VEX skill

This skill is the entrypoint for VEX operations in hve-core. It combines the OpenVEX v0.2.0
specification reference with reusable management playbooks for implementing, reviewing, and
validating VEX documents. The normative reference material below remains the authoritative
source for schema, status logic, and public-source guidance.

VEX management playbooks

Detection, drafting, and attestation are workflow-owned automation. This skill supplies the
reusable procedures, mutation rules, and review criteria. The CVE Analyzer subagent performs the per-CVE exploitability analysis that feeds those workflows.

Implement VEX in a target project

Use this playbook when standing up VEX in a target project. Scaffold the VEX document under
security/vex, wire the vex-detect and vex-draft workflows, reference the PR-body scaffold in
assets/pr-body-scaffold.yml, connect the dedicated reusable VEX
attestation workflow for provenance and OpenVEX-over-SBOM attestation, and set CODEOWNERS on the VEX document.
Use references/vex-status-logic.md and the
vex-standards.instructions.md instructions for the detailed rules.

Review and validate VEX

Use this playbook when reviewing drafted VEX statements. Assess the status determination against
the evidence and confidence bands, honor the document mutation and forbidden-transition contract,
and validate the release attestation output. Attestation generation is owned by the dedicated
reusable VEX attestation workflow, not by the reviewer. The forthcoming tested gate module and
tests will live in this skill so the workflow and interactive entry points can share the same
rules.

VEX statuses

Justification codes for not_affected

When a statement uses not_affected status, it must include a machine-readable justification:

Product identifiers

Products use Package URL (PURL) format
(for example, pkg:npm/@microsoft/hve-core@3.10.0).

Normative references

1. OpenVEX JSON Schema Reference: field definitions, required
   versus optional fields, and example documents.
2. VEX Status Logic: status determination decision tree,
   evidence requirements per status, and forbidden transitions.
3. CVE Data Sources: OSV.dev, NVD, and GitHub Advisory Database
   API references with licensing posture.

Skill layout

• SKILL.md: this file (skill entrypoint).
• references/: normative reference documents.
  • openvex-schema.md: JSON schema reference with field definitions and examples.
  • vex-status-logic.md: status determination decision tree and forbidden transitions.
  • cve-data-sources.md: CVE data source API references and licensing.

Attribution and licensing

The OpenVEX specification reference content in this skill is derived from the OpenVEX Community
specification and remains attributed to the OpenVEX Community. The reusable VEX management
playbooks and the surrounding guidance in this skill are hve-core-authored content. The skill
frontmatter uses a mixed-attribution metadata set so the upstream specification reference and the
hve-core playbooks are clearly distinguished.

Third-Party Attribution