diff --git a/wordpress.org/public_html/wp-content/plugins/plugin-directory/shortcodes/class-upload.php b/wordpress.org/public_html/wp-content/plugins/plugin-directory/shortcodes/class-upload.php
index ea5d8acb0e..c545fea943 100644
--- a/wordpress.org/public_html/wp-content/plugins/plugin-directory/shortcodes/class-upload.php
+++ b/wordpress.org/public_html/wp-content/plugins/plugin-directory/shortcodes/class-upload.php
@@ -97,8 +97,19 @@ public static function display() {
 				wp_verify_nonce( $_POST['_wpnonce'], 'wporg-plugins-upload-' . $_POST['plugin_id'] )
 			)
 		) {
-			$for_plugin    = absint( $_POST['plugin_id'] ?? 0 );
-			$upload_result = $uploader->process_upload( $for_plugin );
+			$for_plugin = absint( $_POST['plugin_id'] ?? 0 );
+
+			// Lock to prevent duplicate submissions from double-clicks or page reloads
+			$lock_key = 'plugin_upload_lock_' . get_current_user_id() . '_' . $for_plugin;
+			if ( false === wp_cache_add( $lock_key, time(), 'wporg-plugins', 5 * MINUTE_IN_SECONDS ) ) {
+				$upload_result = new \WP_Error(
+					'upload_in_progress',
+					__( 'Your previous upload is still being processed. Please wait a moment before trying again.', 'wporg-plugins' )
+				);
+			} else {
+				$upload_result = $uploader->process_upload( $for_plugin );
+				wp_cache_delete( $lock_key, 'wporg-plugins' );
+			}
 
 			if ( is_wp_error( $upload_result ) ) {
 				$type    = 'error';
@@ -368,7 +379,7 @@ public static function display() {
 										<span><?php _e( 'Select File', 'wporg-plugins' ); ?></span>
 									</label>
 
-									<input class="upload-button wp-block-button__link" type="submit" value="<?php esc_attr_e( 'Upload', 'wporg-plugins' ) ?>"/>
+									<input class="upload-button wp-block-button__link" type="submit" value="<?php esc_attr_e( 'Upload', 'wporg-plugins' ); ?>" data-uploading-label="<?php esc_attr_e( 'Uploading…', 'wporg-plugins' ); ?>"/>
 								</form>
 								<?php
 								echo '</div>';
@@ -569,7 +580,7 @@ public static function display() {
 					</label>
 				</p>
 
-				<input id="upload_button" class="wp-block-button__link" type="submit" value="<?php esc_attr_e( 'Upload', 'wporg-plugins' ); ?>"/>
+				<input id="upload_button" class="wp-block-button__link" type="submit" value="<?php esc_attr_e( 'Upload', 'wporg-plugins' ); ?>" data-uploading-label="<?php esc_attr_e( 'Uploading…', 'wporg-plugins' ); ?>"/>
 			</form>
 		<?php endif; // $can_submit_new_plugin
 
diff --git a/wordpress.org/public_html/wp-content/themes/pub/wporg-plugins-2024/js/upload.js b/wordpress.org/public_html/wp-content/themes/pub/wporg-plugins-2024/js/upload.js
index 3212ec6a3f..7e4cc57a1c 100644
--- a/wordpress.org/public_html/wp-content/themes/pub/wporg-plugins-2024/js/upload.js
+++ b/wordpress.org/public_html/wp-content/themes/pub/wporg-plugins-2024/js/upload.js
@@ -49,4 +49,16 @@
 		$(this).hide().parents('ul').find('.plugin-upload-form.hidden').removeClass( 'hidden' );
 	} );
 
+	// Prevent duplicate submissions by disabling the submit button
+	$( 'form.plugin-upload-form' ).on( 'submit', function() {
+		var $button = $(this).find( 'input[type="submit"]' ),
+			uploadingLabel = $button.data( 'uploadingLabel' );
+
+		$button.prop( 'disabled', true );
+
+		if ( uploadingLabel ) {
+			$button.val( uploadingLabel );
+		}
+	} );
+
 })( jQuery );