diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4dd4783597..a9819a6c79 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,9 +2,34 @@
 
 All notable changes to this project will be documented in this file.
 
+## [4.3.8] - 2025-05-06
+
+### Security
+
+- Update dependencies
+- Check scheme on account, profile, and media URLs ([GHSA-x2rc-v5wx-g3m5](https://github.com/mastodon/mastodon/security/advisories/GHSA-x2rc-v5wx-g3m5))
+
+### Added
+
+- Add warning for REDIS_NAMESPACE deprecation at startup (#34581 by @ClearlyClaire)
+- Add built-in context for interaction policies (#34574 by @ClearlyClaire)
+
+### Changed
+
+- Change activity distribution error handling to skip retrying for deleted accounts (#33617 by @ClearlyClaire)
+
+### Removed
+
+- Remove double-query for signed query strings (#34610 by @ClearlyClaire)
+
+### Fixed
+
+- Fix incorrect redirect in response to unauthenticated API requests in limited federation mode (#34549 by @ClearlyClaire)
+- Fix sign-up e-mail confirmation page reloading on error or redirect (#34548 by @ClearlyClaire)
+
 ## [4.3.7] - 2025-04-02
 
-### Add
+### Added
 
 - Add delay to profile updates to debounce them (#34137 by @ClearlyClaire)
 - Add support for paginating partial collections in `SynchronizeFollowersService` (#34272 and #34277 by @ClearlyClaire)
diff --git a/app/javascript/mastodon/actions/importer/normalizer.js b/app/javascript/mastodon/actions/importer/normalizer.js
index c2918ef8d5..2c583f86d4 100644
--- a/app/javascript/mastodon/actions/importer/normalizer.js
+++ b/app/javascript/mastodon/actions/importer/normalizer.js
@@ -77,6 +77,17 @@ export function normalizeStatus(status, normalOldStatus) {
     normalStatus.contentHtml  = emojify(normalStatus.content, emojiMap);
     normalStatus.spoilerHtml  = emojify(escapeTextContentForBrowser(spoilerText), emojiMap);
     normalStatus.hidden       = expandSpoilers ? false : spoilerText.length > 0 || normalStatus.sensitive;
+
+    if (normalStatus.url && !(normalStatus.url.startsWith('http://') || normalStatus.url.startsWith('https://'))) {
+      normalStatus.url = null;
+    }
+
+    normalStatus.url ||= normalStatus.uri;
+
+    normalStatus.media_attachments.forEach(item => {
+      if (item.remote_url && !(item.remote_url.startsWith('http://') || item.remote_url.startsWith('https://')))
+        item.remote_url = null;
+    });
   }
 
   if (normalOldStatus) {
diff --git a/app/javascript/mastodon/models/account.ts b/app/javascript/mastodon/models/account.ts
index 4d95d24757..2666059b40 100644
--- a/app/javascript/mastodon/models/account.ts
+++ b/app/javascript/mastodon/models/account.ts
@@ -144,5 +144,10 @@ export function createAccountFromServerJSON(serverJSON: ApiAccountJSON) {
     ),
     note_emojified: emojify(accountJSON.note, emojiMap),
     note_plain: unescapeHTML(accountJSON.note),
+    url:
+      accountJSON.url.startsWith('http://') ||
+      accountJSON.url.startsWith('https://')
+        ? accountJSON.url
+        : accountJSON.uri,
   });
 }
diff --git a/app/lib/activitypub/parser/media_attachment_parser.rb b/app/lib/activitypub/parser/media_attachment_parser.rb
index 56b8b23f84..bcbf92214f 100644
--- a/app/lib/activitypub/parser/media_attachment_parser.rb
+++ b/app/lib/activitypub/parser/media_attachment_parser.rb
@@ -15,13 +15,15 @@ class ActivityPub::Parser::MediaAttachmentParser
   end
 
   def remote_url
-    Addressable::URI.parse(@json['url'])&.normalize&.to_s
+    url = Addressable::URI.parse(@json['url'])&.normalize&.to_s
+    url unless unsupported_uri_scheme?(url)
   rescue Addressable::URI::InvalidURIError
     nil
   end
 
   def thumbnail_remote_url
-    Addressable::URI.parse(@json['icon'].is_a?(Hash) ? @json['icon']['url'] : @json['icon'])&.normalize&.to_s
+    url = Addressable::URI.parse(@json['icon'].is_a?(Hash) ? @json['icon']['url'] : @json['icon'])&.normalize&.to_s
+    url unless unsupported_uri_scheme?(url)
   rescue Addressable::URI::InvalidURIError
     nil
   end
diff --git a/app/lib/activitypub/parser/status_parser.rb b/app/lib/activitypub/parser/status_parser.rb
index 1c5a9310ec..266ec60dba 100644
--- a/app/lib/activitypub/parser/status_parser.rb
+++ b/app/lib/activitypub/parser/status_parser.rb
@@ -29,7 +29,10 @@ class ActivityPub::Parser::StatusParser
   end
 
   def url
-    url_to_href(@object['url'], 'text/html') if @object['url'].present?
+    return if @object['url'].blank?
+
+    url = url_to_href(@object['url'], 'text/html')
+    url unless unsupported_uri_scheme?(url)
   end
 
   def text
diff --git a/app/lib/activitypub/tag_manager.rb b/app/lib/activitypub/tag_manager.rb
index 2fe707e79b..4d83a9b823 100644
--- a/app/lib/activitypub/tag_manager.rb
+++ b/app/lib/activitypub/tag_manager.rb
@@ -4,6 +4,7 @@ require 'singleton'
 
 class ActivityPub::TagManager
   include Singleton
+  include JsonLdHelper
   include RoutingHelper
 
   CONTEXT = 'https://www.w3.org/ns/activitystreams'
@@ -17,7 +18,7 @@ class ActivityPub::TagManager
   end
 
   def url_for(target)
-    return target.url if target.respond_to?(:local?) && !target.local?
+    return unsupported_uri_scheme?(target.url) ? nil : target.url if target.respond_to?(:local?) && !target.local?
 
     return unless target.respond_to?(:object_type)
 
diff --git a/docker-compose.yml b/docker-compose.yml
index a5b38093dd..5ccb0a77d6 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/glitch-soc/mastodon:v4.3.7
+    image: ghcr.io/glitch-soc/mastodon:v4.3.8
     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/glitch-soc/mastodon-streaming:v4.3.7
+    image: ghcr.io/glitch-soc/mastodon-streaming:v4.3.8
     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/glitch-soc/mastodon:v4.3.7
+    image: ghcr.io/glitch-soc/mastodon:v4.3.8
     restart: always
     env_file: .env.production
     command: bundle exec sidekiq
diff --git a/lib/mastodon/version.rb b/lib/mastodon/version.rb
index 88e82a2b58..841472f7de 100644
--- a/lib/mastodon/version.rb
+++ b/lib/mastodon/version.rb
@@ -17,7 +17,7 @@ module Mastodon
     end
 
     def default_prerelease
-      'alpha.4'
+      'alpha.5'
     end
 
     def prerelease