diff --git a/.upgradenotes/MDL-86607-2025091110293140.yml b/.upgradenotes/MDL-86607-2025091110293140.yml
new file mode 100644
index 00000000000..ae9e444a750
--- /dev/null
+++ b/.upgradenotes/MDL-86607-2025091110293140.yml
@@ -0,0 +1,7 @@
+issueNumber: MDL-86607
+notes:
+  mod_feedback:
+    - message: >-
+        The method `feedback_init_feedback_session()` has been deprecated, along
+        with all other direct access to `$SESSION` from the module
+      type: deprecated
diff --git a/public/mod/feedback/deprecatedlib.php b/public/mod/feedback/deprecatedlib.php
index fde0df01845..b1b78b94789 100644
--- a/public/mod/feedback/deprecatedlib.php
+++ b/public/mod/feedback/deprecatedlib.php
@@ -34,3 +34,19 @@ function feedback_check_is_switchrole(): bool {
     \core\deprecation::emit_deprecation(__FUNCTION__);
     return isset($USER->switchrole) && is_array($USER->switchrole) && count($USER->switchrole) > 0;
 }
+
+/**
+ * Initialize the feedback session
+ *
+ * @deprecated since Moodle 5.2 - please do not use this function any more
+ */
+#[\core\attribute\deprecated(since: '5.2', mdl: 'MDL-86607')]
+function feedback_init_feedback_session() {
+    global $SESSION;
+    \core\deprecation::emit_deprecation(__FUNCTION__);
+    if (!empty($SESSION)) {
+        if (!isset($SESSION->feedback) || !is_object($SESSION->feedback)) {
+            $SESSION->feedback = new stdClass();
+        }
+    }
+}
diff --git a/public/mod/feedback/edit.php b/public/mod/feedback/edit.php
index e5f8b488393..f5c584a8851 100644
--- a/public/mod/feedback/edit.php
+++ b/public/mod/feedback/edit.php
@@ -25,8 +25,6 @@
 require_once('../../config.php');
 require_once('lib.php');
 
-feedback_init_feedback_session();
-
 $id = required_param('id', PARAM_INT);
 
 if (($formdata = data_submitted()) AND !confirm_sesskey()) {
diff --git a/public/mod/feedback/edit_item.php b/public/mod/feedback/edit_item.php
index 00c5c4e8d93..14a5fc69886 100644
--- a/public/mod/feedback/edit_item.php
+++ b/public/mod/feedback/edit_item.php
@@ -25,8 +25,6 @@
 require_once("../../config.php");
 require_once("lib.php");
 
-feedback_init_feedback_session();
-
 $itemid = optional_param('id', false, PARAM_INT);
 if (!$itemid) {
     $cmid = required_param('cmid', PARAM_INT);
diff --git a/public/mod/feedback/item/captcha/print_captcha.php b/public/mod/feedback/item/captcha/print_captcha.php
deleted file mode 100644
index 7d7e6d0447f..00000000000
--- a/public/mod/feedback/item/captcha/print_captcha.php
+++ /dev/null
@@ -1,124 +0,0 @@
-<?php
-// This file is part of Moodle - http://moodle.org/
-//
-// Moodle is free software: you can redistribute it and/or modify
-// it under the terms of the GNU General Public License as published by
-// the Free Software Foundation, either version 3 of the License, or
-// (at your option) any later version.
-//
-// Moodle is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU General Public License for more details.
-//
-// You should have received a copy of the GNU General Public License
-// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
-
-require_once('../../../../config.php');
-
-$id = required_param('id', PARAM_INT);
-
-$PAGE->set_url('/mod/feedback/item/captcha/print_captcha.php', array('id'=>$id));
-
-if ($id) {
-    if (! $cm = get_coursemodule_from_id('feedback', $id)) {
-        throw new \moodle_exception('invalidcoursemodule');
-    }
-
-    if (! $course = $DB->get_record("course", array("id"=>$cm->course))) {
-        throw new \moodle_exception('coursemisconf');
-    }
-
-    if (! $feedback = $DB->get_record("feedback", array("id"=>$cm->instance))) {
-        throw new \moodle_exception('invalidcoursemodule');
-    }
-}
-
-if (!isset($SESSION->feedback->item->captcha)) {
-    throw new \moodle_exception('captchanotset', 'feedback');
-}
-
-$height = 40;
-$charcount = $SESSION->feedback->item->captcha->charcount;
-$fontfile = $CFG->libdir.'/default.ttf';
-
-$ttfbox = imagettfbbox ( 30, 0, $fontfile, 'H' );//the text to measure
-$charwidth = $ttfbox[2];
-
-$width = $charcount * $charwidth;
-
-$scale = 0.3;
-$elipsesize = intval((($width + $height)/2) / 5);
-$factor_x = intval($width * $scale);
-$factor_y = intval($height * $scale);
-
-//I split the colors in three ranges
-//given are the max-min-values
-$colors = array(array(0, 40), array(50, 200), array(210, 255));
-list($col_text1, $col_el, $col_text2) = $colors;
-
-//if the text is in color_1 so the elipses can be in color_2 or color_3
-//if the text is in color_2 so the elipses can be in color_1 or color_3
-//and so on.
-$textcolnum = rand(1, 3);
-
-//create the numbers to print out
-$nums = array();
-for ($i = 0; $i < $charcount; $i++) {
-    $nums[] = rand(0, 9); //Ziffern von 0-
-}
-
-//to draw enough elipses so I draw 0.2 * width and 0.2 * height
-//we need th colors for that
-$properties = array();
-for ($x = 0; $x < $factor_x; $x++) {
-    for ($y = 0; $y < $factor_y; $y++) {
-        $propobj = new stdClass();
-        $propobj->x = intval($x / $scale);
-        $propobj->y = intval($y / $scale);
-        $propobj->red = get_random_color($col_el[0], $col_el[1]);
-        $propobj->green = get_random_color($col_el[0], $col_el[1]);
-        $propobj->blue = get_random_color($col_el[0], $col_el[1]);
-        $properties[] = $propobj;
-    }
-}
-shuffle($properties);
-
-// create a blank image
-$image = imagecreatetruecolor($width, $height);
-$bg = imagecolorallocate($image, 0, 0, 0);
-for ($i = 0; $i < ($factor_x * $factor_y); $i++) {
-    $propobj = $properties[$i];
-    // choose a color for the ellipse
-    $col_ellipse = imagecolorallocate($image, $propobj->red, $propobj->green, $propobj->blue);
-    // draw the white ellipse
-    imagefilledellipse($image, $propobj->x, $propobj->y, $elipsesize, $elipsesize, $col_ellipse);
-}
-
-$checkchar = '';
-for ($i = 0; $i < $charcount; $i++) {
-    $colnum = rand(1, 2);
-    $textcol = new stdClass();
-    $textcol->red = get_random_color(${'col_text'.$colnum}[0], ${'col_text'.$colnum}[1]);
-    $textcol->green = get_random_color(${'col_text'.$colnum}[0], ${'col_text'.$colnum}[1]);
-    $textcol->blue = get_random_color(${'col_text'.$colnum}[0], ${'col_text'.$colnum}[1]);
-    $color_text = imagecolorallocate($image, $textcol->red, $textcol->green, $textcol->blue);
-    $angle_text = rand(-20, 20);
-    $left_text = $i * $charwidth;
-    $text = $nums[$i];
-    $checkchar .= $text;
-    imagettftext($image, 30, $angle_text, $left_text, 35, $color_text, $fontfile, $text);
-}
-
-$SESSION->feedback->item->captcha->checkchar = $checkchar;
-
-// output the picture
-header("Content-type: image/png");
-imagepng($image);
-
-function get_random_color($val1 = 0, $val2 = 255) {
-    $min = $val1 < $val2 ? $val1 : $val2;
-    $max = $val1 > $val2 ? $val1 : $val2;
-
-    return rand($min, $max);
-}
diff --git a/public/mod/feedback/lang/en/deprecated.txt b/public/mod/feedback/lang/en/deprecated.txt
index eadd0955797..76074f24116 100644
--- a/public/mod/feedback/lang/en/deprecated.txt
+++ b/public/mod/feedback/lang/en/deprecated.txt
@@ -1 +1,2 @@
-public,mod_feedback
\ No newline at end of file
+public,mod_feedback
+selected_dump,mod_feedback
diff --git a/public/mod/feedback/lang/en/feedback.php b/public/mod/feedback/lang/en/feedback.php
index bb0785a9f5f..b08d8e0a150 100644
--- a/public/mod/feedback/lang/en/feedback.php
+++ b/public/mod/feedback/lang/en/feedback.php
@@ -270,7 +270,6 @@ $string['search:activity'] = 'Feedback - activity information';
 $string['search_course'] = 'Search course';
 $string['searchcourses'] = 'Search courses';
 $string['searchcourses_help'] = 'Search for the code or name of the course(s) that you wish to associate with this feedback.';
-$string['selected_dump'] = 'Selected indexes of $SESSION variable are dumped below:';
 $string['send'] = 'Send';
 $string['send_message'] = 'Send notification';
 $string['show_all'] = 'Show all';
@@ -310,3 +309,6 @@ $string['whatfor'] = 'How would you like to apply the template?';
 
 // Deprecated since Moodle 4.5.
 $string['public'] = 'Public';
+
+// Deprecated since Moodle 5.2.
+$string['selected_dump'] = 'Selected indexes of $SESSION variable are dumped below:';
diff --git a/public/mod/feedback/lib.php b/public/mod/feedback/lib.php
index e78e473cff1..555ddfc8145 100644
--- a/public/mod/feedback/lib.php
+++ b/public/mod/feedback/lib.php
@@ -2745,16 +2745,6 @@ function feedback_extend_settings_navigation(settings_navigation $settings, navi
     }
 }
 
-function feedback_init_feedback_session() {
-    //initialize the feedback-Session - not nice at all!!
-    global $SESSION;
-    if (!empty($SESSION)) {
-        if (!isset($SESSION->feedback) OR !is_object($SESSION->feedback)) {
-            $SESSION->feedback = new stdClass();
-        }
-    }
-}
-
 /**
  * Return a list of page types
  * @param string $pagetype current page type