diff --git a/.github/workflows/plugin-ci-workflow.yml b/.github/workflows/plugin-ci-workflow.yml
index 86237dc..3840fa2 100644
--- a/.github/workflows/plugin-ci-workflow.yml
+++ b/.github/workflows/plugin-ci-workflow.yml
@@ -143,7 +143,7 @@ jobs:
       run: sudo apt-get update
     
     - name: Install System Dependencies
-      run: sudo apt-get install -y apache2 snmp snmpd rrdtool fping libapache2-mod-php${{ matrix.php }}
+      run: sudo apt-get install -y apache2 snmp snmpd rrdtool fping
     
     - name: Start SNMPD Agent and Test
       run: |
diff --git a/functions.php b/functions.php
index 1e54c13..2a147b7 100644
--- a/functions.php
+++ b/functions.php
@@ -47,6 +47,10 @@ function syslog_include_js() {
 	<?php
 }
 
+function syslog_json_encode_for_script($value) {
+	return json_encode($value, JSON_HEX_TAG | JSON_HEX_AMP | JSON_HEX_APOS | JSON_HEX_QUOT);
+}
+
 function syslog_allow_edits() {
 	global $config;
 
diff --git a/setup.php b/setup.php
index 46d0333..f31eeba 100644
--- a/setup.php
+++ b/setup.php
@@ -1608,6 +1608,30 @@ function syslog_utilities_action($action) {
 	}
 
 	if ($action == 'purge_syslog_hosts') {
+		if ($_SERVER['REQUEST_METHOD'] !== 'POST') {
+			cacti_log('WARNING: syslog purge blocked -- non-POST request', false, 'SYSLOG');
+			raise_message('syslog_method_error', __('Invalid request. Please try again.', 'syslog'), MESSAGE_LEVEL_ERROR);
+			header('Location: utilities.php');
+			exit;
+		}
+
+		// csrf_check($fatal) returns bool; $fatal=false tells the helper not to
+		// die/exit on failure so we can log and redirect with a user-visible
+		// message ourselves.
+		if (function_exists('csrf_check')) {
+			if (!csrf_check(false)) {
+				cacti_log('WARNING: syslog purge blocked -- CSRF token validation failed', false, 'SYSLOG');
+				raise_message('syslog_csrf_error', __('Invalid request. Please try again.', 'syslog'), MESSAGE_LEVEL_ERROR);
+				header('Location: utilities.php');
+				exit;
+			}
+		} else {
+			cacti_log('WARNING: syslog purge blocked -- CSRF validation unavailable', false, 'SYSLOG');
+			raise_message('syslog_csrf_unavailable', __('Invalid request. Please try again.', 'syslog'), MESSAGE_LEVEL_ERROR);
+			header('Location: utilities.php');
+			exit;
+		}
+
 		$records = 0;
 
 		syslog_db_execute('DELETE FROM syslog_hosts
@@ -1660,7 +1684,50 @@ function syslog_utilities_list() {
 
 	<tr class='even'>
 		<td>
-			<a class='hyperLink' href='utilities.php?action=purge_syslog_hosts'><?php print __('Purge Syslog Devices', 'syslog'); ?></a>
+			<input id='syslog_purge_hosts' type='button' value='<?php print __esc('Purge Syslog Devices', 'syslog');?>'>
+			<div id='syslog_purge_dialog' style='display:none;'>
+				<p><?php print __esc('Are you sure you want to purge stale Syslog devices?', 'syslog');?></p>
+			</div>
+			<script type='text/javascript'>
+			$(function() {
+				$('#syslog_purge_hosts').on('click', function() {
+					$('#syslog_purge_dialog').dialog({
+						title: <?php print json_encode(__('Confirm Purge', 'syslog'), JSON_HEX_TAG | JSON_HEX_AMP | JSON_HEX_APOS | JSON_HEX_QUOT);?>,
+						minHeight: 80,
+						minWidth: 400,
+						resizable: false,
+						draggable: true,
+						buttons: {
+							'Cancel': {
+								text: <?php print json_encode(__('Cancel', 'syslog'), JSON_HEX_TAG | JSON_HEX_AMP | JSON_HEX_APOS | JSON_HEX_QUOT);?>,
+								id: 'btnPurgeCancel',
+								click: function() {
+									$(this).dialog('close');
+								}
+							},
+							'Continue': {
+								text: <?php print json_encode(__('Continue', 'syslog'), JSON_HEX_TAG | JSON_HEX_AMP | JSON_HEX_APOS | JSON_HEX_QUOT);?>,
+								id: 'btnPurgeContinue',
+								click: function() {
+									$(this).dialog('close');
+
+									var postData = {
+										action: 'purge_syslog_hosts',
+										__csrf_magic: csrfMagicToken
+									};
+
+									if (typeof postUrl == 'function') {
+										postUrl({url: 'utilities.php', noState: true}, postData);
+									} else {
+										loadPageUsingPost('utilities.php', postData);
+									}
+								}
+							}
+						}
+					});
+				});
+			});
+			</script>
 		</td>
 		<td>
 			<?php print __('This menu pick provides a means to remove Devices that are no longer reporting into Cacti\'s syslog server.', 'syslog'); ?>
diff --git a/syslog.php b/syslog.php
index 0d1c45c..80165d8 100644
--- a/syslog.php
+++ b/syslog.php
@@ -1184,11 +1184,11 @@ function syslog_filter($sql_where, $tab) {
 	?>
 	<script type='text/javascript'>
 	initSyslogMain({
-		pageTab: '<?php print get_request_var('tab'); ?>',
-		placeHolder: '<?php print __esc('Enter a search term', 'syslog'); ?>',
-		noneSelectedText: '<?php print __esc('Select Device(s)', 'syslog'); ?>',
-		devicesSelectedText: '<?php print __esc('Devices Selected', 'syslog'); ?>',
-		allDevicesText: '<?php print __esc('All Devices Selected', 'syslog'); ?>'
+		pageTab: <?php print syslog_json_encode_for_script(get_request_var('tab'));?>,
+		placeHolder: <?php print syslog_json_encode_for_script(__('Enter a search term', 'syslog'));?>,
+		noneSelectedText: <?php print syslog_json_encode_for_script(__('Select Device(s)', 'syslog'));?>,
+		devicesSelectedText: <?php print syslog_json_encode_for_script(__('Devices Selected', 'syslog'));?>,
+		allDevicesText: <?php print syslog_json_encode_for_script(__('All Devices Selected', 'syslog'));?>
 	});
 	</script>
 	<?php
diff --git a/syslog_alerts.php b/syslog_alerts.php
index 6f47c97..b97f8c9 100644
--- a/syslog_alerts.php
+++ b/syslog_alerts.php
@@ -210,7 +210,7 @@ function form_actions() {
 		<td align='right' class='saveRow'>
 			<input type='hidden' name='action' value='actions'>
 			<input type='hidden' name='selected_items' value='" . (isset($alert_array) ? serialize($alert_array) : '') . "'>
-			<input type='hidden' name='drp_action' value='" . get_request_var('drp_action') . "'>
+			<input type='hidden' name='drp_action' value='" . html_escape(get_request_var('drp_action')) . "'>
 			$save_html
 		</td>
 	</tr>";
@@ -856,7 +856,7 @@ function syslog_alerts() {
 		'user'     => [__('By User', 'syslog'), 'DESC']
 	];
 
-	$nav = html_nav_bar('syslog_alerts.php?filter=' . get_request_var('filter'), MAX_DISPLAY_PAGES, get_request_var('page'), $rows, $total_rows, cacti_sizeof($display_text) + 1, __('Alerts', 'syslog'), 'page', 'main');
+	$nav = html_nav_bar('syslog_alerts.php?filter=' . rawurlencode(get_request_var('filter')), MAX_DISPLAY_PAGES, get_request_var('page'), $rows, $total_rows, cacti_sizeof($display_text) + 1, __('Alerts', 'syslog'), 'page', 'main');
 
 	form_start('syslog_alerts.php', 'chk');
 
diff --git a/syslog_removal.php b/syslog_removal.php
index e047e68..b8768b5 100644
--- a/syslog_removal.php
+++ b/syslog_removal.php
@@ -234,7 +234,7 @@ function form_actions() {
 		<td class='saveRow'>
 			<input type='hidden' name='action' value='actions'>
 			<input type='hidden' name='selected_items' value='" . (isset($removal_array) ? serialize($removal_array) : '') . "'>
-			<input type='hidden' name='drp_action' value='" . get_request_var('drp_action') . "'>
+			<input type='hidden' name='drp_action' value='" . html_escape(get_request_var('drp_action')) . "'>
 			$save_html
 		</td>
 	</tr>";
@@ -667,7 +667,7 @@ function syslog_removal() {
 
 	form_start('syslog_removal.php', 'chk');
 
-	$nav = html_nav_bar('syslog_removal.php?filter=' . get_request_var('filter'), MAX_DISPLAY_PAGES, get_request_var('page'), $rows, $total_rows, cacti_sizeof($display_text) + 1, __('Rules', 'syslog'), 'page', 'main');
+	$nav = html_nav_bar('syslog_removal.php?filter=' . rawurlencode(get_request_var('filter')), MAX_DISPLAY_PAGES, get_request_var('page'), $rows, $total_rows, cacti_sizeof($display_text) + 1, __('Rules', 'syslog'), 'page', 'main');
 
 	print $nav;
 
diff --git a/syslog_reports.php b/syslog_reports.php
index fd7b212..ecf2ef1 100644
--- a/syslog_reports.php
+++ b/syslog_reports.php
@@ -206,7 +206,7 @@ function form_actions() {
 		<td align='right' class='saveRow'>
 			<input type='hidden' name='action' value='actions'>
 			<input type='hidden' name='selected_items' value='" . (isset($report_array) ? serialize($report_array) : '') . "'>
-			<input type='hidden' name='drp_action' value='" . get_request_var('drp_action') . "'>
+			<input type='hidden' name='drp_action' value='" . html_escape(get_request_var('drp_action')) . "'>
 			$save_html
 		</td>
 	</tr>\n";
@@ -704,7 +704,7 @@ function syslog_report() {
 		'user'     => [__('By User', 'syslog'), 'DESC']
 	];
 
-	$nav = html_nav_bar('syslog_reports.php?filter=' . get_request_var('filter'), MAX_DISPLAY_PAGES, get_request_var('page'), $rows, $total_rows, cacti_sizeof($display_text) + 1, __('Reports', 'syslog'), 'page', 'main');
+	$nav = html_nav_bar('syslog_reports.php?filter=' . rawurlencode(get_request_var('filter')), MAX_DISPLAY_PAGES, get_request_var('page'), $rows, $total_rows, cacti_sizeof($display_text) + 1, __('Reports', 'syslog'), 'page', 'main');
 
 	form_start('syslog_reports.php', 'chk');
 
diff --git a/tests/regression/issue259_csrf_purge_test.php b/tests/regression/issue259_csrf_purge_test.php
new file mode 100644
index 0000000..b2d30c0
--- /dev/null
+++ b/tests/regression/issue259_csrf_purge_test.php
@@ -0,0 +1,120 @@
+<?php
+/*
+ * Source-scan lint for the #259 purge-syslog-hosts CSRF hardening.
+ *
+ * This is a lint, NOT a behavioral test. It asserts that the expected
+ * CSRF-enforcement snippets exist in setup.php so regressions that
+ * silently delete the POST/csrf_check/JS-post-flow are caught at CI
+ * time. A full behavioral test would require bootstrapping Cacti's
+ * session, CSRF token, and database, which this plugin's regression
+ * harness cannot currently provide.
+ *
+ * If the guard is refactored in a way that preserves the strings but
+ * breaks the logic, this lint will NOT catch it — follow-up issue for
+ * real behavioral coverage once a DB-backed test harness exists.
+ */
+
+$setup = file_get_contents(dirname(__DIR__, 2) . '/setup.php');
+
+if ($setup === false) {
+	fwrite(STDERR, "Failed to read setup.php\n");
+	exit(1);
+}
+
+$required = array(
+	"if (\$_SERVER['REQUEST_METHOD'] !== 'POST')",
+	"if (function_exists('csrf_check'))",
+	"if (!csrf_check(false))",
+	"__csrf_magic: csrfMagicToken"
+);
+
+foreach ($required as $snippet) {
+	if (strpos($setup, $snippet) === false) {
+		fwrite(STDERR, "Missing expected CSRF hardening snippet: $snippet\n");
+		exit(1);
+	}
+}
+
+if (strpos($setup, "href='utilities.php?action=purge_syslog_hosts'") !== false) {
+	fwrite(STDERR, "Legacy GET purge link still present.\n");
+	exit(1);
+}
+
+// Verify fail-closed: the else branch (csrf_check unavailable) must reject, not fall through.
+// Assert globally safe properties rather than parsing the else block via brittle regex.
+
+// The fallback path must not attempt manual token checking
+if (strpos($setup, "\$_POST['__csrf_magic']") !== false) {
+	fwrite(STDERR, "Fallback CSRF branch must not check token presence; must fail closed.\n");
+	exit(1);
+}
+
+// The fallback path must log the blocked attempt
+if (strpos($setup, "cacti_log('WARNING: syslog purge blocked") === false) {
+	fwrite(STDERR, "Fail-closed branch must call cacti_log() to audit blocked purge attempts.\n");
+	exit(1);
+}
+
+// Log message must name the specific failure reason for incident response
+if (strpos($setup, 'CSRF validation unavailable') === false) {
+	fwrite(STDERR, "Log message must specify 'CSRF validation unavailable' for operational clarity.\n");
+	exit(1);
+}
+
+// Verify JS confirm() uses json_encode, not __esc() inside JS string
+if (preg_match("/confirm\(\s*'/", $setup)) {
+	fwrite(STDERR, "JS confirm() must use json_encode() for safe encoding, not __esc() in a quoted string.\n");
+	exit(1);
+}
+
+if (strpos($setup, 'json_encode(__(') === false) {
+	fwrite(STDERR, "Expected json_encode(__(...)) for JS-safe encoding of confirm message.\n");
+	exit(1);
+}
+
+// Verify json_encode uses JSON_HEX_TAG to prevent </script> breakout in HTML script context
+if (strpos($setup, 'JSON_HEX_TAG') === false) {
+	fwrite(STDERR, "json_encode() must use JSON_HEX_TAG to prevent script-context breakout.\n");
+	exit(1);
+}
+
+if (strpos($setup, 'JSON_HEX_AMP') === false) {
+	fwrite(STDERR, "json_encode() must use JSON_HEX_AMP to escape ampersands in script context.\n");
+	exit(1);
+}
+
+if (strpos($setup, 'JSON_HEX_APOS') === false) {
+	fwrite(STDERR, "json_encode() must use JSON_HEX_APOS.\n");
+	exit(1);
+}
+
+if (strpos($setup, 'JSON_HEX_QUOT') === false) {
+	fwrite(STDERR, "json_encode() must use JSON_HEX_QUOT.\n");
+	exit(1);
+}
+
+// Verify user-facing messages do not expose CSRF internals (log messages may use "CSRF")
+if (preg_match('/raise_message\\s*\\(\\s*[^,]+,\\s*__\\(\\s*([\'\"])[^\'\"]*CSRF[^\'\"]*\\1/si', $setup)) {
+	fwrite(STDERR, "User-facing raise_message must not expose CSRF internals to end users.\n");
+	exit(1);
+}
+
+// Verify generic user-facing message is present
+if (strpos($setup, "Invalid request. Please try again.") === false) {
+	fwrite(STDERR, "Fail-closed branch must use generic 'Invalid request. Please try again.' message.\n");
+	exit(1);
+}
+
+// Verify fail-closed raise_message uses MESSAGE_LEVEL_ERROR severity
+if (strpos($setup, "raise_message('syslog_csrf_unavailable', __('Invalid request. Please try again.', 'syslog'), MESSAGE_LEVEL_ERROR)") === false) {
+	fwrite(STDERR, "Fail-closed branch raise_message must use MESSAGE_LEVEL_ERROR severity.\n");
+	exit(1);
+}
+
+// Verify log message does not expose internal function name
+if (strpos($setup, 'csrf_check() unavailable') !== false) {
+	fwrite(STDERR, "Log message must not name internal validation function.\n");
+	exit(1);
+}
+
+echo "issue259_csrf_purge_test passed\n";
diff --git a/tests/regression/issue279_bulk_form_and_nav_encoding_test.php b/tests/regression/issue279_bulk_form_and_nav_encoding_test.php
new file mode 100644
index 0000000..63f8e23
--- /dev/null
+++ b/tests/regression/issue279_bulk_form_and_nav_encoding_test.php
@@ -0,0 +1,58 @@
+<?php
+
+$targets = array(
+	'syslog_removal.php' => file_get_contents(__DIR__ . '/../../syslog_removal.php'),
+	'syslog_alerts.php'  => file_get_contents(__DIR__ . '/../../syslog_alerts.php'),
+	'syslog_reports.php' => file_get_contents(__DIR__ . '/../../syslog_reports.php'),
+	'syslog.php'         => file_get_contents(__DIR__ . '/../../syslog.php'),
+);
+
+foreach ($targets as $file => $contents) {
+	if ($contents === false) {
+		fwrite(STDERR, "Unable to read $file\n");
+		exit(1);
+	}
+}
+
+foreach (array('syslog_removal.php', 'syslog_alerts.php', 'syslog_reports.php') as $file) {
+	if (strpos($targets[$file], "html_escape(get_request_var('drp_action'))") === false) {
+		fwrite(STDERR, "Expected escaped drp_action hidden field in $file\n");
+		exit(1);
+	}
+
+	if (strpos($targets[$file], "rawurlencode(get_request_var('filter'))") === false) {
+		fwrite(STDERR, "Expected URL-encoded filter nav value in $file\n");
+		exit(1);
+	}
+
+	if (strpos($targets[$file], "<input type='hidden' name='drp_action' value='\" . get_request_var('drp_action') . \"'>") !== false) {
+		fwrite(STDERR, "Legacy raw drp_action hidden field remains in $file\n");
+		exit(1);
+	}
+}
+
+$syslog = $targets['syslog.php'];
+
+if (strpos($syslog, "pageTab: <?php print syslog_json_encode_for_script(get_request_var('tab'));?>,") === false) {
+	fwrite(STDERR, "Expected JSON-encoded syslog pageTab value\n");
+	exit(1);
+}
+
+foreach (array(
+	"syslog_json_encode_for_script(__('Enter a search term', 'syslog'))",
+	"syslog_json_encode_for_script(__('Select Device(s)', 'syslog'))",
+	"syslog_json_encode_for_script(__('Devices Selected', 'syslog'))",
+	"syslog_json_encode_for_script(__('All Devices Selected', 'syslog'))",
+) as $needle) {
+	if (strpos($syslog, $needle) === false) {
+		fwrite(STDERR, "Expected JS-safe initSyslogMain text encoding\n");
+		exit(1);
+	}
+}
+
+if (strpos($syslog, "pageTab: '<?php print get_request_var('tab'); ?>'") !== false) {
+	fwrite(STDERR, "Legacy raw pageTab JS assignment still present\n");
+	exit(1);
+}
+
+echo "OK\n";