diff --git a/packages/model-catalog-core/src/provider-model-id-normalization.test.ts b/packages/model-catalog-core/src/provider-model-id-normalization.test.ts
index 5a8a904e716d30..c49863d74f346c 100644
--- a/packages/model-catalog-core/src/provider-model-id-normalization.test.ts
+++ b/packages/model-catalog-core/src/provider-model-id-normalization.test.ts
@@ -6,6 +6,24 @@ import {
   stripSelfProviderModelPrefix,
 } from "./provider-model-id-normalization.js";
 
+function poisonedModelIdNormalizationRecord() {
+  return Object.defineProperty({}, "modelIdNormalization", {
+    get() {
+      throw new Error("model id normalization metadata exploded");
+    },
+  });
+}
+
+function poisonedModelIdNormalizationProvidersRecord() {
+  return {
+    modelIdNormalization: Object.defineProperty({}, "providers", {
+      get() {
+        throw new Error("model id normalization providers exploded");
+      },
+    }),
+  };
+}
+
 describe("provider model id policy normalization", () => {
   it("applies manifest policies before built-in provider normalization", () => {
     const policies = collectManifestModelIdNormalizationPolicies([
@@ -27,6 +45,40 @@ describe("provider model id policy normalization", () => {
     );
   });
 
+  it("skips unreadable manifest model id normalization records", () => {
+    const policies = collectManifestModelIdNormalizationPolicies([
+      {
+        modelIdNormalization: {
+          providers: {
+            custom: {
+              prefixWhenBare: "vendor",
+            },
+          },
+        },
+      },
+      poisonedModelIdNormalizationRecord(),
+      poisonedModelIdNormalizationProvidersRecord(),
+      {
+        modelIdNormalization: {
+          providers: {
+            "Google-Vertex": {
+              aliases: {
+                pro: "gemini-3-pro",
+              },
+            },
+          },
+        },
+      },
+    ]);
+
+    expect(normalizeStaticProviderModelIdWithPolicies("custom", "latest", policies)).toBe(
+      "vendor/latest",
+    );
+    expect(normalizeStaticProviderModelIdWithPolicies("google-vertex", "pro", policies)).toBe(
+      "gemini-3.1-pro-preview",
+    );
+  });
+
   it("normalizes provider-prefixed Google catalog refs behind gateway prefixes", () => {
     expect(
       normalizeConfiguredProviderCatalogModelId(
diff --git a/packages/model-catalog-core/src/provider-model-id-normalization.ts b/packages/model-catalog-core/src/provider-model-id-normalization.ts
index 8a66b92ed1af0a..6ba34b51dd1816 100644
--- a/packages/model-catalog-core/src/provider-model-id-normalization.ts
+++ b/packages/model-catalog-core/src/provider-model-id-normalization.ts
@@ -29,7 +29,13 @@ export function collectManifestModelIdNormalizationPolicies(
 ): Map<string, ManifestModelIdNormalizationProvider> {
   const policies = new Map<string, ManifestModelIdNormalizationProvider>();
   for (const plugin of plugins) {
-    for (const [provider, policy] of Object.entries(plugin.modelIdNormalization?.providers ?? {})) {
+    let providers: Record<string, ManifestModelIdNormalizationProvider> | undefined;
+    try {
+      providers = plugin.modelIdNormalization?.providers;
+    } catch {
+      continue;
+    }
+    for (const [provider, policy] of Object.entries(providers ?? {})) {
       policies.set(normalizeLowercaseStringOrEmpty(provider), policy);
     }
   }