Publish vat test data

CITATION.cff

@@ -4,7 +4,7 @@ title: "VAT Test Data"
 abstract: "National-format VAT numbers for every country in the VAT registry, with the 2026 standard rate. Format-shaped synthetic values for fixtures; not verified registrations."
 type: dataset
 license: CC0-1.0
-version: "1.0.1"
+version: "1.0.2"
 date-released: "2026-10-01"
 authors:
   - name: "StanzaAPI"

README.md

@@ -41,7 +41,7 @@ https://stanzaapi.com/datasets/vat
 
 ## Security: adversarial corpus
 
-This dataset ships a catalogued **adversarial corpus** of 10 hostile inputs
+This dataset ships a catalogued **adversarial corpus** of 12 hostile inputs
 (injection, XXE, resource exhaustion, encoding attacks, validation bypass, structural confusion,
 and prompt injection for AI agents) with the safe expected behaviour. See
 [`adversarial/`](adversarial/) or the [hub](https://stanzaapi.com/datasets/adversarial).

adversarial/vat-adversarial.json

@@ -4,7 +4,7 @@
   "source": "https://stanzaapi.com/datasets/vat/adversarial",
   "license": "CC0-1.0",
   "format": "vat",
-  "count": 10,
+  "count": 12,
   "cases": [
     {
       "id": "vat-crlf-header-injection",
@@ -115,6 +115,30 @@
       "expected": "Reject or normalise to EL, per VIES. Document the choice.",
       "rationale": "Greece uses the EL prefix for VAT; GR is the ISO country code, not the VAT prefix.",
       "cwe": "CWE-20"
+    },
+    {
+      "id": "vat-zero-width-separator",
+      "format": "vat",
+      "category": "encoding",
+      "severity": "high",
+      "title": "Zero-width separator inside the VAT number",
+      "payload": "DE​123456789",
+      "expected": "Reject zero-width and format characters rather than trimming them; the bytes stored must equal the characters displayed.",
+      "rationale": "A zero-width space renders invisibly, so the number looks valid in every UI while the stored bytes differ from the visible value. A layer that trims and a layer that compares raw will disagree.",
+      "cwe": "CWE-176",
+      "evades": "national pattern (after trimming)"
+    },
+    {
+      "id": "vat-format-valid-not-registered",
+      "format": "vat",
+      "category": "validation-bypass",
+      "severity": "critical",
+      "title": "Well-formed VAT number that is not a registered VIES number",
+      "payload": "DE123456789",
+      "expected": "Report format validity and registration as separate facts. Offline syntax validation must never be surfaced as VIES confirmation.",
+      "rationale": "The classic zero-rating trap: the syntax passes, so a checkout that equates \"format valid\" with \"VIES valid\" applies 0% VAT to a supply that is not zero-rated. Only a live VIES lookup can confirm registration.",
+      "cwe": "CWE-20",
+      "evades": "national pattern (the number is well-formed)"
     }
   ]
 }