FIX: Only allow intergers for page params.

app/controllers/list_controller.rb

@@ -331,6 +331,8 @@ class ListController < ApplicationController
 
   def build_topic_list_options
     options = {}
+    params[:page] = params[:page].to_i rescue 1
+
     TopicQuery.public_valid_options.each do |key|
       options[key] = params[key]
     end

spec/requests/list_controller_spec.rb

@@ -3,6 +3,18 @@ require 'rails_helper'
 RSpec.describe ListController do
   let(:topic) { Fabricate(:topic) }
 
+  describe '#index' do
+    it "doesn't throw an error with a negative page" do
+      get "/#{Discourse.anonymous_filters[1]}", params: { page: -1024 }
+      expect(response).to be_success
+    end
+
+    it "doesn't throw an error with page params as an array" do
+      get "/#{Discourse.anonymous_filters[1]}", params: { page: ['7'] }
+      expect(response).to be_success
+    end
+  end
+
   describe 'titles for crawler layout' do
     it 'has no title for the default URL' do
       topic