diff --git a/internal/plugins/backends/ollama/plugin.go b/internal/plugins/backends/ollama/plugin.go
index 6633c02b..585aebb3 100644
--- a/internal/plugins/backends/ollama/plugin.go
+++ b/internal/plugins/backends/ollama/plugin.go
@@ -138,7 +138,7 @@ func fetchVersion(ctx context.Context, client *http.Client, nativeRoot string) (
 	if resp.StatusCode < 200 || resp.StatusCode > 299 {
 		return "", fmt.Errorf("version HTTP status %d", resp.StatusCode)
 	}
-	body, err := io.ReadAll(resp.Body)
+	body, err := io.ReadAll(io.LimitReader(resp.Body, 1024*1024))
 	if err != nil {
 		return "", err
 	}
diff --git a/internal/plugins/backends/ollama/plugin_test.go b/internal/plugins/backends/ollama/plugin_test.go
index 731ad8ae..eba4fd77 100644
--- a/internal/plugins/backends/ollama/plugin_test.go
+++ b/internal/plugins/backends/ollama/plugin_test.go
@@ -138,3 +138,22 @@ func TestNew_VersionDetectionAndResponses(t *testing.T) {
 		t.Fatal("expected explicitly disabled responses to not be supported")
 	}
 }
+
+func TestFetchVersion_OOM_Regression(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(200)
+		chunk := make([]byte, 1024*1024)
+		for i := 0; i < 50; i++ {
+			w.Write(chunk)
+		}
+	}))
+	defer srv.Close()
+
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	_, err := fetchVersion(ctx, srv.Client(), srv.URL)
+	if err == nil {
+		t.Fatalf("expected error due to large payload or invalid json, got none")
+	}
+}
diff --git a/internal/plugins/backends/opencodecommon/catalog/loader.go b/internal/plugins/backends/opencodecommon/catalog/loader.go
index aff49042..6c8b9ee8 100644
--- a/internal/plugins/backends/opencodecommon/catalog/loader.go
+++ b/internal/plugins/backends/opencodecommon/catalog/loader.go
@@ -132,7 +132,7 @@ func getJSON(ctx context.Context, client *http.Client, endpoint string, headers
 		body, _ := io.ReadAll(io.LimitReader(resp.Body, 4096))
 		return nil, fmt.Errorf("opencodecommon: model discovery HTTP status %d: %s", resp.StatusCode, strings.TrimSpace(string(body)))
 	}
-	body, err := io.ReadAll(resp.Body)
+	body, err := io.ReadAll(io.LimitReader(resp.Body, 10*1024*1024))
 	if err != nil {
 		return nil, fmt.Errorf("opencodecommon: model discovery read: %w", err)
 	}
diff --git a/internal/plugins/backends/opencodecommon/catalog/loader_test.go b/internal/plugins/backends/opencodecommon/catalog/loader_test.go
index 00e94bed..6850cdde 100644
--- a/internal/plugins/backends/opencodecommon/catalog/loader_test.go
+++ b/internal/plugins/backends/opencodecommon/catalog/loader_test.go
@@ -115,3 +115,22 @@ func TestLoadModelEntries_noFallbackOnRemoteFailure(t *testing.T) {
 		t.Fatal("expected error without fallback")
 	}
 }
+
+func TestGetJSON_OOM_Regression(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(200)
+		chunk := make([]byte, 1024*1024)
+		for i := 0; i < 50; i++ {
+			w.Write(chunk)
+		}
+	}))
+	defer srv.Close()
+
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	_, err := getJSON(ctx, srv.Client(), srv.URL, nil)
+	if err == nil {
+		t.Fatalf("expected error due to large payload or invalid json, got none")
+	}
+}