fix(release): reject malformed publication JSON bytes

scripts/release-publication-receipt.mjs

@@ -92,8 +92,14 @@ function requireRegularFile(path, label, maxBytes = MAX_JSON_BYTES) {
 
 function readJson(path, label) {
   requireRegularFile(path, label);
+  let text;
   try {
-    const value = JSON.parse(readFileSync(path, "utf8"));
+    text = new TextDecoder("utf-8", { fatal: true }).decode(readFileSync(path));
+  } catch (error) {
+    fail(`${label} is not valid UTF-8: ${error instanceof Error ? error.message : String(error)}`);
+  }
+  try {
+    const value = JSON.parse(text);
     if (!value || typeof value !== "object" || Array.isArray(value)) {
       fail(`${label} must contain a JSON object`);
     }

test/immutable-release-publication.test.ts

@@ -267,6 +267,28 @@ describe("immutable buyer release publication", () => {
     }
   });
 
+  it("fails closed on malformed UTF-8 publication JSON", () => {
+    const temp = mkdtempSync(join(tmpdir(), "noema-immutable-release-invalid-utf8-"));
+    try {
+      const { fixture, result } = runReceipt(temp, (value) => {
+        writeFileSync(
+          value.policyPath,
+          Buffer.concat([
+            Buffer.from('{"enabled":true,"enforced_by_owner":true,"evidence_note":"', "utf8"),
+            Buffer.from([0x80]),
+            Buffer.from('"}', "utf8"),
+          ]),
+        );
+      });
+
+      expect(result.status).not.toBe(0);
+      expect(result.stderr).toContain("UTF-8");
+      expect(() => readFileSync(fixture.outputPath)).toThrow();
+    } finally {
+      rmSync(temp, { recursive: true, force: true });
+    }
+  });
+
   it("isolates publication permission and verifies every durable release asset", () => {
     const workflow = readFileSync(".github/workflows/release-evidence.yml", "utf8");
 
@@ -308,4 +330,4 @@ describe("immutable buyer release publication", () => {
     expect(documentation).toContain("gh release verify-asset");
     expect(documentation).toContain("does not prove deployment");
   });
-});
+});