diff --git a/administrator/components/com_media/config.xml b/administrator/components/com_media/config.xml
index 9a04b26b2caab..5adbbc172720e 100644
--- a/administrator/components/com_media/config.xml
+++ b/administrator/components/com_media/config.xml
@@ -55,7 +55,7 @@
 			type="textarea"
 			label="COM_MEDIA_FIELD_RESTRICT_UPLOADS_EXTENSIONS_LABEL"
 			description="COM_MEDIA_FIELD_RESTRICT_UPLOADS_EXTENSIONS_DESC"
-			default="bmp,gif,jpg,jpeg,png,webp,ico,mp3,mp4,odg,odp,ods,odt,pdf,png,ppt,txt,xcf,xls,csv"
+			default="bmp,gif,jpg,jpeg,png,webp,avif,ico,mp3,mp4,odg,odp,ods,odt,pdf,png,ppt,txt,xcf,xls,csv"
 			showon="restrict_uploads:1"
 		/>
 
@@ -77,7 +77,7 @@
 			type="textarea"
 			label="COM_MEDIA_FIELD_LEGAL_IMAGE_EXTENSIONS_LABEL"
 			description="COM_MEDIA_FIELD_LEGAL_IMAGE_EXTENSIONS_DESC"
-			default="bmp,gif,jpg,jpeg,png,webp"
+			default="bmp,gif,jpg,jpeg,png,webp,avif"
 		/>
 
 		<field
@@ -116,7 +116,7 @@
 			type="textarea"
 			label="COM_MEDIA_FIELD_LEGAL_MIME_TYPES_LABEL"
 			description="COM_MEDIA_FIELD_LEGAL_MIME_TYPES_DESC"
-			default="image/jpeg,image/gif,image/png,image/bmp,image/webp,audio/ogg,audio/mpeg,audio/mp4,video/mp4,video/mpeg,video/quicktime,video/webm,application/msword,application/excel,application/pdf,application/powerpoint,text/plain,application/x-zip"
+			default="image/jpeg,image/gif,image/png,image/bmp,image/webp,image/avif,audio/ogg,audio/mpeg,audio/mp4,video/mp4,video/mpeg,video/quicktime,video/webm,application/msword,application/excel,application/pdf,application/powerpoint,text/plain,application/x-zip"
 			showon="restrict_uploads:1"
 		/>
 	</fieldset>
diff --git a/installation/sql/mysql/base.sql b/installation/sql/mysql/base.sql
index 8b0e61fda97c5..191f3d0e7d8fb 100644
--- a/installation/sql/mysql/base.sql
+++ b/installation/sql/mysql/base.sql
@@ -165,7 +165,7 @@ INSERT INTO `#__extensions` (`package_id`, `name`, `type`, `element`, `folder`,
 (0, 'com_installer', 'component', 'com_installer', '', 1, 1, 1, 1, 1, '', '{"cachetimeout":"6","minimum_stability":"4"}', ''),
 (0, 'com_languages', 'component', 'com_languages', '', 1, 1, 1, 1, 1, '', '{"administrator":"en-GB","site":"en-GB"}', ''),
 (0, 'com_login', 'component', 'com_login', '', 1, 1, 1, 1, 1, '', '', ''),
-(0, 'com_media', 'component', 'com_media', '', 1, 1, 0, 1, 1, '', '{"upload_maxsize":"10","file_path":"images","image_path":"images","restrict_uploads":"1","allowed_media_usergroup":"3","restrict_uploads_extensions":"bmp,gif,jpg,jpeg,png,webp,ico,mp3,m4a,mp4a,ogg,mp4,mp4v,mpeg,mov,odg,odp,ods,odt,pdf,png,ppt,txt,xcf,xls,csv","check_mime":"1","image_extensions":"bmp,gif,jpg,png,jpeg,webp","audio_extensions":"mp3,m4a,mp4a,ogg","video_extensions":"mp4,mp4v,mpeg,mov,webm","doc_extensions":"odg,odp,ods,odt,pdf,ppt,txt,xcf,xls,csv","ignore_extensions":"","upload_mime":"image\\/jpeg,image\\/gif,image\\/png,image\\/bmp,image\\/webp,audio\\/ogg,audio\\/mpeg,audio\\/mp4,video\\/mp4,video\\/webm,video\\/mpeg,video\\/quicktime,application\\/msword,application\\/excel,application\\/pdf,application\\/powerpoint,text\\/plain,application\\/x-zip"}', ''),
+(0, 'com_media', 'component', 'com_media', '', 1, 1, 0, 1, 1, '', '{"upload_maxsize":"10","file_path":"images","image_path":"images","restrict_uploads":"1","allowed_media_usergroup":"3","restrict_uploads_extensions":"bmp,gif,jpg,jpeg,png,webp,avif,ico,mp3,m4a,mp4a,ogg,mp4,mp4v,mpeg,mov,odg,odp,ods,odt,pdf,png,ppt,txt,xcf,xls,csv","check_mime":"1","image_extensions":"bmp,gif,jpg,png,jpeg,webp,avif","audio_extensions":"mp3,m4a,mp4a,ogg","video_extensions":"mp4,mp4v,mpeg,mov,webm","doc_extensions":"odg,odp,ods,odt,pdf,ppt,txt,xcf,xls,csv","ignore_extensions":"","upload_mime":"image\\/jpeg,image\\/gif,image\\/png,image\\/bmp,image\\/webp,image\\/avif,audio\\/ogg,audio\\/mpeg,audio\\/mp4,video\\/mp4,video\\/webm,video\\/mpeg,video\\/quicktime,application\\/msword,application\\/excel,application\\/pdf,application\\/powerpoint,text\\/plain,application\\/x-zip"}', ''),
 (0, 'com_menus', 'component', 'com_menus', '', 1, 1, 1, 1, 1, '', '{"page_title":"","show_page_heading":0,"page_heading":"","pageclass_sfx":""}', ''),
 (0, 'com_messages', 'component', 'com_messages', '', 1, 1, 1, 1, 1, '', '', ''),
 (0, 'com_modules', 'component', 'com_modules', '', 1, 1, 1, 1, 1, '', '', ''),
diff --git a/installation/sql/postgresql/base.sql b/installation/sql/postgresql/base.sql
index f34727daa8f30..4ce86b03fd053 100644
--- a/installation/sql/postgresql/base.sql
+++ b/installation/sql/postgresql/base.sql
@@ -171,7 +171,7 @@ INSERT INTO "#__extensions" ("package_id", "name", "type", "element", "folder",
 (0, 'com_installer', 'component', 'com_installer', '', 1, 1, 1, 1, 1, '', '{"cachetimeout":"6","minimum_stability":"4"}', '', 0, 0),
 (0, 'com_languages', 'component', 'com_languages', '', 1, 1, 1, 1, 1, '', '{"administrator":"en-GB","site":"en-GB"}', '', 0, 0),
 (0, 'com_login', 'component', 'com_login', '', 1, 1, 1, 1, 1, '', '', '', 0, 0),
-(0, 'com_media', 'component', 'com_media', '', 1, 1, 0, 1, 1, '', '{"upload_maxsize":"10","file_path":"images","image_path":"images","restrict_uploads":"1","allowed_media_usergroup":"3","restrict_uploads_extensions":"bmp,gif,jpg,jpeg,png,ico,webp,mp3,m4a,mp4a,ogg,mp4,mp4v,mpeg,mov,odg,odp,ods,odt,pdf,png,ppt,txt,xcf,xls,csv","check_mime":"1","image_extensions":"bmp,gif,jpg,png,jpeg,webp","audio_extensions":"mp3,m4a,mp4a,ogg","video_extensions":"mp4,mp4v,mpeg,mov,webm","doc_extensions":"odg,odp,ods,odt,pdf,ppt,txt,xcf,xls,csv","ignore_extensions":"","upload_mime":"image\\/jpeg,image\\/gif,image\\/png,image\\/bmp,image\\/webp,audio\\/ogg,audio\\/mpeg,audio\\/mp4,video\\/mp4,video\\/webm,video\\/mpeg,video\\/quicktime,application\\/msword,application\\/excel,application\\/pdf,application\\/powerpoint,text\\/plain,application\\/x-zip"}', '', 0, 0),
+(0, 'com_media', 'component', 'com_media', '', 1, 1, 0, 1, 1, '', '{"upload_maxsize":"10","file_path":"images","image_path":"images","restrict_uploads":"1","allowed_media_usergroup":"3","restrict_uploads_extensions":"bmp,gif,jpg,jpeg,png,ico,webp,avif,mp3,m4a,mp4a,ogg,mp4,mp4v,mpeg,mov,odg,odp,ods,odt,pdf,png,ppt,txt,xcf,xls,csv","check_mime":"1","image_extensions":"bmp,gif,jpg,png,jpeg,webp,avif","audio_extensions":"mp3,m4a,mp4a,ogg","video_extensions":"mp4,mp4v,mpeg,mov,webm","doc_extensions":"odg,odp,ods,odt,pdf,ppt,txt,xcf,xls,csv","ignore_extensions":"","upload_mime":"image\\/jpeg,image\\/gif,image\\/png,image\\/bmp,image\\/webp,image\\/avif,audio\\/ogg,audio\\/mpeg,audio\\/mp4,video\\/mp4,video\\/webm,video\\/mpeg,video\\/quicktime,application\\/msword,application\\/excel,application\\/pdf,application\\/powerpoint,text\\/plain,application\\/x-zip"}', '', 0, 0),
 (0, 'com_menus', 'component', 'com_menus', '', 1, 1, 1, 1, 1, '', '{"page_title":"","show_page_heading":0,"page_heading":"","pageclass_sfx":""}', '', 0, 0),
 (0, 'com_messages', 'component', 'com_messages', '', 1, 1, 1, 1, 1, '', '', '', 0, 0),
 (0, 'com_modules', 'component', 'com_modules', '', 1, 1, 1, 1, 1, '', '', '', 0, 0),
diff --git a/libraries/src/Helper/MediaHelper.php b/libraries/src/Helper/MediaHelper.php
index 47c892df539ee..b7c24ca376d8e 100644
--- a/libraries/src/Helper/MediaHelper.php
+++ b/libraries/src/Helper/MediaHelper.php
@@ -54,7 +54,7 @@ class MediaHelper
      */
     public static function isImage($fileName)
     {
-        static $imageTypes = 'xcf|odg|gif|jpg|jpeg|png|bmp|webp';
+        static $imageTypes = 'xcf|odg|gif|jpg|jpeg|png|bmp|webp|avif';
 
         return preg_match("/\.(?:$imageTypes)$/i", $fileName);
     }
@@ -141,8 +141,8 @@ private function checkMimeType($mime, $component = 'com_media'): bool
         if ($params->get('check_mime', 1)) {
             $allowedMime = $params->get(
                 'upload_mime',
-                'image/jpeg,image/gif,image/png,image/bmp,image/webp,application/msword,application/excel,' .
-                    'application/pdf,application/powerpoint,text/plain,application/x-zip'
+                'image/jpeg,image/gif,image/png,image/bmp,image/webp,image/avif,application/msword,' .
+                    'application/excel,application/pdf,application/powerpoint,text/plain,application/x-zip'
             );
 
             // Get the mime type configuration
@@ -182,7 +182,7 @@ public static function checkFileExtension($extension, $component = 'com_media',
             return false;
         }
 
-        $allowable = array_map('trim', explode(',', $params->get('restrict_uploads_extensions', 'bmp,gif,jpg,jpeg,png,webp,ico,mp3,m4a,mp4a,ogg,mp4,mp4v,mpeg,mov,odg,odp,ods,odt,pdf,ppt,txt,xcf,xls,csv')));
+        $allowable = array_map('trim', explode(',', $params->get('restrict_uploads_extensions', 'bmp,gif,jpg,jpeg,png,webp,avif,ico,mp3,m4a,mp4a,ogg,mp4,mp4v,mpeg,mov,odg,odp,ods,odt,pdf,ppt,txt,xcf,xls,csv')));
         $ignored   = array_map('trim', explode(',', $params->get('ignore_extensions', '')));
 
         if ($extension == '' || $extension == false || (!\in_array($extension, $allowable, true) && !\in_array($extension, $ignored, true))) {
@@ -268,7 +268,7 @@ public function canUpload($file, $component = 'com_media', $allowedExecutables =
         }
 
         if ($params->get('restrict_uploads', 1)) {
-            $allowedExtensions = array_map('trim', explode(',', $params->get('restrict_uploads_extensions', 'bmp,gif,jpg,jpeg,png,webp,ico,mp3,m4a,mp4a,ogg,mp4,mp4v,mpeg,mov,odg,odp,ods,odt,pdf,png,ppt,txt,xcf,xls,csv')));
+            $allowedExtensions = array_map('trim', explode(',', $params->get('restrict_uploads_extensions', 'bmp,gif,jpg,jpeg,png,webp,avif,ico,mp3,m4a,mp4a,ogg,mp4,mp4v,mpeg,mov,odg,odp,ods,odt,pdf,png,ppt,txt,xcf,xls,csv')));
 
             if (\in_array($filetype, $allowedExtensions)) {
                 // If tmp_name is empty, then the file was bigger than the PHP limit