diff --git a/CHANGELOG.md b/CHANGELOG.md
index 39e975479..cfbc450d7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,25 @@
 
 All notable changes to this project will be documented in this file.
 
+## [4.5.6] - 2026-02-03
+
+### Security
+
+- Fix ActivityPub collection caching logic for pinned posts and featured tags not checking blocked accounts ([GHSA-ccpr-m53r-mfwr](https://github.com/mastodon/mastodon/security/advisories/GHSA-ccpr-m53r-mfwr))
+
+### Changed
+
+- Shorten caching of quote posts pending approval (#37570 and #37592 by @ClearlyClaire)
+
+### Fixed
+
+- Fix relationship cache not being cleared when handling account migrations (#37664 by @ClearlyClaire)
+- Fix quote cancel button not appearing after edit then delete-and-redraft (#37066 by @PGrayCS)
+- Fix followers with profile subscription (bell icon) being notified of post edits (#37646 by @ClearlyClaire)
+- Fix error when encountering invalid tag in updated object (#37635 by @ClearlyClaire)
+- Fix cross-server conversation tracking (#37559 by @ClearlyClaire)
+- Fix recycled connections not being immediately closed (#37335 and #37674 by @ClearlyClaire and @shleeable)
+
 ## [4.5.5] - 2026-01-20
 
 ### Security
diff --git a/app/controllers/activitypub/collections_controller.rb b/app/controllers/activitypub/collections_controller.rb
index c80db3500..752b843c8 100644
--- a/app/controllers/activitypub/collections_controller.rb
+++ b/app/controllers/activitypub/collections_controller.rb
@@ -4,17 +4,31 @@ class ActivityPub::CollectionsController < ActivityPub::BaseController
   vary_by -> { 'Signature' if authorized_fetch_mode? }
 
   before_action :require_account_signature!, if: :authorized_fetch_mode?
+  before_action :check_authorization
   before_action :set_items
   before_action :set_size
   before_action :set_type
 
   def show
     expires_in 3.minutes, public: public_fetch_mode?
-    render_with_cache json: collection_presenter, content_type: 'application/activity+json', serializer: ActivityPub::CollectionSerializer, adapter: ActivityPub::Adapter
+
+    if @unauthorized
+      render json: collection_presenter, content_type: 'application/activity+json', serializer: ActivityPub::CollectionSerializer, adapter: ActivityPub::Adapter
+    else
+      render_with_cache json: collection_presenter, content_type: 'application/activity+json', serializer: ActivityPub::CollectionSerializer, adapter: ActivityPub::Adapter
+    end
   end
 
   private
 
+  def check_authorization
+    # Because in public fetch mode we cache the response, there would be no
+    # benefit from performing the check below, since a blocked account or domain
+    # would likely be served the cache from the reverse proxy anyway
+
+    @unauthorized = authorized_fetch_mode? && !signed_request_account.nil? && (@account.blocking?(signed_request_account) || (!signed_request_account.domain.nil? && @account.domain_blocking?(signed_request_account.domain)))
+  end
+
   def set_items
     case params[:id]
     when 'featured'
@@ -57,11 +71,7 @@ class ActivityPub::CollectionsController < ActivityPub::BaseController
   end
 
   def for_signed_account
-    # Because in public fetch mode we cache the response, there would be no
-    # benefit from performing the check below, since a blocked account or domain
-    # would likely be served the cache from the reverse proxy anyway
-
-    if authorized_fetch_mode? && !signed_request_account.nil? && (@account.blocking?(signed_request_account) || (!signed_request_account.domain.nil? && @account.domain_blocking?(signed_request_account.domain)))
+    if @unauthorized
       []
     else
       yield
diff --git a/app/controllers/statuses_controller.rb b/app/controllers/statuses_controller.rb
index e673faca0..65db807d1 100644
--- a/app/controllers/statuses_controller.rb
+++ b/app/controllers/statuses_controller.rb
@@ -29,7 +29,7 @@ class StatusesController < ApplicationController
       end
 
       format.json do
-        expires_in 3.minutes, public: true if @status.distributable? && public_fetch_mode?
+        expires_in @status.quote&.pending? ? 5.seconds : 3.minutes, public: true if @status.distributable? && public_fetch_mode?
         render_with_cache json: @status, content_type: 'application/activity+json', serializer: ActivityPub::NoteSerializer, adapter: ActivityPub::Adapter
       end
     end
diff --git a/app/javascript/mastodon/components/status.jsx b/app/javascript/mastodon/components/status.jsx
index 2a8c9bfb2..aac58b31f 100644
--- a/app/javascript/mastodon/components/status.jsx
+++ b/app/javascript/mastodon/components/status.jsx
@@ -145,6 +145,7 @@ class Status extends ImmutablePureComponent {
     'hidden',
     'unread',
     'pictureInPicture',
+    'onQuoteCancel',
   ];
 
   state = {
diff --git a/app/lib/activitypub/activity/create.rb b/app/lib/activitypub/activity/create.rb
index 43c7bb1fe..a7d2be35e 100644
--- a/app/lib/activitypub/activity/create.rb
+++ b/app/lib/activitypub/activity/create.rb
@@ -379,6 +379,7 @@ class ActivityPub::Activity::Create < ActivityPub::Activity
   def conversation_from_uri(uri)
     return nil if uri.nil?
     return Conversation.find_by(id: OStatus::TagManager.instance.unique_tag_to_local_id(uri, 'Conversation')) if OStatus::TagManager.instance.local_id?(uri)
+    return ActivityPub::TagManager.instance.uri_to_resource(uri, Conversation) if ActivityPub::TagManager.instance.local_uri?(uri)
 
     begin
       Conversation.find_or_create_by!(uri: uri)
diff --git a/app/lib/activitypub/tag_manager.rb b/app/lib/activitypub/tag_manager.rb
index 3174d1792..40adb5737 100644
--- a/app/lib/activitypub/tag_manager.rb
+++ b/app/lib/activitypub/tag_manager.rb
@@ -241,12 +241,6 @@ class ActivityPub::TagManager
     !host.nil? && (::TagManager.instance.local_domain?(host) || ::TagManager.instance.web_domain?(host))
   end
 
-  def uri_to_local_id(uri, param = :id)
-    path_params = Rails.application.routes.recognize_path(uri)
-    path_params[:username] = Rails.configuration.x.local_domain if path_params[:controller] == 'instance_actors'
-    path_params[param]
-  end
-
   def uris_to_local_accounts(uris)
     usernames = []
     ids = []
@@ -264,6 +258,14 @@ class ActivityPub::TagManager
     uri_to_resource(uri, Account)
   end
 
+  def uri_to_local_conversation(uri)
+    path_params = Rails.application.routes.recognize_path(uri)
+    return unless path_params[:controller] == 'activitypub/contexts'
+
+    account_id, conversation_id = path_params[:id].split('-')
+    Conversation.find_by(parent_account_id: account_id, id: conversation_id)
+  end
+
   def uri_to_resource(uri, klass)
     return if uri.nil?
 
@@ -271,6 +273,8 @@ class ActivityPub::TagManager
       case klass.name
       when 'Account'
         uris_to_local_accounts([uri]).first
+      when 'Conversation'
+        uri_to_local_conversation(uri)
       else
         StatusFinder.new(uri).status
       end
diff --git a/app/lib/connection_pool/shared_timed_stack.rb b/app/lib/connection_pool/shared_timed_stack.rb
index 14a5285c4..8a13f4473 100644
--- a/app/lib/connection_pool/shared_timed_stack.rb
+++ b/app/lib/connection_pool/shared_timed_stack.rb
@@ -70,6 +70,7 @@ class ConnectionPool::SharedTimedStack
     if @created == @max && !@queue.empty?
       throw_away_connection = @queue.pop
       @tagged_queue[throw_away_connection.site].delete(throw_away_connection)
+      throw_away_connection.close
       @create_block.call(preferred_tag)
     elsif @created != @max
       connection = @create_block.call(preferred_tag)
diff --git a/app/lib/ostatus/tag_manager.rb b/app/lib/ostatus/tag_manager.rb
index cb0c9f896..7d0f23c4d 100644
--- a/app/lib/ostatus/tag_manager.rb
+++ b/app/lib/ostatus/tag_manager.rb
@@ -11,16 +11,12 @@ class OStatus::TagManager
   def unique_tag_to_local_id(tag, expected_type)
     return nil unless local_id?(tag)
 
-    if ActivityPub::TagManager.instance.local_uri?(tag)
-      ActivityPub::TagManager.instance.uri_to_local_id(tag)
-    else
-      matches = Regexp.new("objectId=([\\d]+):objectType=#{expected_type}").match(tag)
-      matches[1] unless matches.nil?
-    end
+    matches = Regexp.new("objectId=([\\d]+):objectType=#{expected_type}").match(tag)
+    matches[1] unless matches.nil?
   end
 
   def local_id?(id)
-    id.start_with?("tag:#{Rails.configuration.x.local_domain}") || ActivityPub::TagManager.instance.local_uri?(id)
+    id.start_with?("tag:#{Rails.configuration.x.local_domain}")
   end
 
   def uri_for(target)
diff --git a/app/models/quote.rb b/app/models/quote.rb
index 4ad393e3a..e4f3b823f 100644
--- a/app/models/quote.rb
+++ b/app/models/quote.rb
@@ -47,6 +47,8 @@ class Quote < ApplicationRecord
 
   def accept!
     update!(state: :accepted)
+
+    reset_parent_cache! if attribute_previously_changed?(:state)
   end
 
   def reject!
@@ -75,6 +77,15 @@ class Quote < ApplicationRecord
 
   private
 
+  def reset_parent_cache!
+    return if status_id.nil?
+
+    Rails.cache.delete("v3:statuses/#{status_id}")
+
+    # This clears the web cache for the ActivityPub representation
+    Rails.cache.delete("statuses/show:v3:statuses/#{status_id}")
+  end
+
   def set_accounts
     self.account = status.account
     self.quoted_account = quoted_status&.account
diff --git a/app/services/activitypub/process_status_update_service.rb b/app/services/activitypub/process_status_update_service.rb
index 1cdf0b483..c45454fc7 100644
--- a/app/services/activitypub/process_status_update_service.rb
+++ b/app/services/activitypub/process_status_update_service.rb
@@ -204,7 +204,11 @@ class ActivityPub::ProcessStatusUpdateService < BaseService
 
   def update_tags!
     previous_tags = @status.tags.to_a
-    current_tags = @status.tags = Tag.find_or_create_by_names(@raw_tags)
+    current_tags = @status.tags = @raw_tags.flat_map do |tag|
+      Tag.find_or_create_by_names([tag]).filter(&:valid?)
+    rescue ActiveRecord::RecordInvalid
+      []
+    end
 
     return unless @status.distributable?
 
diff --git a/app/workers/feed_insert_worker.rb b/app/workers/feed_insert_worker.rb
index e883daf3e..b0c9c9181 100644
--- a/app/workers/feed_insert_worker.rb
+++ b/app/workers/feed_insert_worker.rb
@@ -53,7 +53,7 @@ class FeedInsertWorker
 
   def notify?(filter_result)
     return false if @type != :home || @status.reblog? || (@status.reply? && @status.in_reply_to_account_id != @status.account_id) ||
-                    filter_result == :filter
+                    update? || filter_result == :filter
 
     Follow.find_by(account: @follower, target_account: @status.account)&.notify?
   end
diff --git a/app/workers/move_worker.rb b/app/workers/move_worker.rb
index 1a5745a86..d0103dc66 100644
--- a/app/workers/move_worker.rb
+++ b/app/workers/move_worker.rb
@@ -64,6 +64,16 @@ class MoveWorker
                    .in_batches do |follows|
       ListAccount.where(follow: follows).in_batches.update_all(account_id: @target_account.id)
       num_moved += follows.update_all(target_account_id: @target_account.id)
+
+      # Clear any relationship cache, since callbacks are not called
+      Rails.cache.delete_multi(follows.flat_map do |follow|
+        [
+          ['relationship', follow.account_id, follow.target_account_id],
+          ['relationship', follow.target_account_id, follow.account_id],
+          ['relationship', follow.account_id, @target_account.id],
+          ['relationship', @target_account.id, follow.account_id],
+        ]
+      end)
     end
 
     num_moved
diff --git a/docker-compose.yml b/docker-compose.yml
index 52d2a83f4..caff99be1 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -59,7 +59,7 @@ services:
   web:
     # You can uncomment the following line if you want to not use the prebuilt image, for example if you have local code changes
     # build: .
-    image: ghcr.io/mastodon/mastodon:v4.5.5
+    image: ghcr.io/mastodon/mastodon:v4.5.6
     restart: always
     env_file: .env.production
     command: bundle exec puma -C config/puma.rb
@@ -83,7 +83,7 @@ services:
     # build:
     #   dockerfile: ./streaming/Dockerfile
     #   context: .
-    image: ghcr.io/mastodon/mastodon-streaming:v4.5.5
+    image: ghcr.io/mastodon/mastodon-streaming:v4.5.6
     restart: always
     env_file: .env.production
     command: node ./streaming/index.js
@@ -102,7 +102,7 @@ services:
   sidekiq:
     # You can uncomment the following line if you want to not use the prebuilt image, for example if you have local code changes
     # build: .
-    image: ghcr.io/mastodon/mastodon:v4.5.5
+    image: ghcr.io/mastodon/mastodon:v4.5.6
     restart: always
     env_file: .env.production
     command: bundle exec sidekiq
diff --git a/lib/mastodon/version.rb b/lib/mastodon/version.rb
index 8fa37f225..9a7415aa8 100644
--- a/lib/mastodon/version.rb
+++ b/lib/mastodon/version.rb
@@ -13,7 +13,7 @@ module Mastodon
     end
 
     def patch
-      5
+      6
     end
 
     def default_prerelease
diff --git a/spec/lib/activitypub/activity/create_spec.rb b/spec/lib/activitypub/activity/create_spec.rb
index 1e8a2a29d..19b6014af 100644
--- a/spec/lib/activitypub/activity/create_spec.rb
+++ b/spec/lib/activitypub/activity/create_spec.rb
@@ -471,7 +471,7 @@ RSpec.describe ActivityPub::Activity::Create do
         end
       end
 
-      context 'with a reply' do
+      context 'with a reply without explicitly setting a conversation' do
         let(:original_status) { Fabricate(:status) }
 
         let(:object_json) do
@@ -493,6 +493,30 @@ RSpec.describe ActivityPub::Activity::Create do
         end
       end
 
+      context 'with a reply explicitly setting a conversation' do
+        let(:original_status) { Fabricate(:status) }
+
+        let(:object_json) do
+          build_object(
+            inReplyTo: ActivityPub::TagManager.instance.uri_for(original_status),
+            conversation: ActivityPub::TagManager.instance.uri_for(original_status.conversation),
+            context: ActivityPub::TagManager.instance.uri_for(original_status.conversation)
+          )
+        end
+
+        it 'creates status' do
+          expect { subject.perform }.to change(sender.statuses, :count).by(1)
+
+          status = sender.statuses.first
+
+          expect(status).to_not be_nil
+          expect(status.thread).to eq original_status
+          expect(status.reply?).to be true
+          expect(status.in_reply_to_account).to eq original_status.account
+          expect(status.conversation).to eq original_status.conversation
+        end
+      end
+
       context 'with mentions' do
         let(:recipient) { Fabricate(:account) }
 
diff --git a/spec/lib/activitypub/tag_manager_spec.rb b/spec/lib/activitypub/tag_manager_spec.rb
index 6cbb58055..7571d03f0 100644
--- a/spec/lib/activitypub/tag_manager_spec.rb
+++ b/spec/lib/activitypub/tag_manager_spec.rb
@@ -612,14 +612,6 @@ RSpec.describe ActivityPub::TagManager do
     end
   end
 
-  describe '#uri_to_local_id' do
-    let(:account) { Fabricate(:account, id_scheme: :username_ap_id) }
-
-    it 'returns the local ID' do
-      expect(subject.uri_to_local_id(subject.uri_for(account), :username)).to eq account.username
-    end
-  end
-
   describe '#uris_to_local_accounts' do
     it 'returns the expected local accounts' do
       account = Fabricate(:account)
diff --git a/spec/services/activitypub/process_status_update_service_spec.rb b/spec/services/activitypub/process_status_update_service_spec.rb
index 9d63c5f1f..9dc1ece33 100644
--- a/spec/services/activitypub/process_status_update_service_spec.rb
+++ b/spec/services/activitypub/process_status_update_service_spec.rb
@@ -258,6 +258,7 @@ RSpec.describe ActivityPub::ProcessStatusUpdateService do
           tag: [
             { type: 'Hashtag', name: 'foo' },
             { type: 'Hashtag', name: 'bar' },
+            { type: 'Hashtag', name: '#2024' },
           ],
         }
       end