diff --git a/backend/lib/validators.js b/backend/lib/validators.js
index 47cc0c0..cebfd84 100644
--- a/backend/lib/validators.js
+++ b/backend/lib/validators.js
@@ -195,6 +195,22 @@ function sanitizeString(str) {
   return cleaned.trim();
 }
 
+/**
+ * Валидация идентификатора сервера для использования в S3-ключах и путях.
+ * Запрещает path traversal (.., /, \) и небезопасные символы.
+ * @param {string} serverId - идентификатор сервера
+ * @param {object} opts - { maxLength: number } (по умолчанию 128)
+ * @returns {boolean}
+ */
+function isValidServerId(serverId, opts = {}) {
+  if (!serverId || typeof serverId !== 'string') return false;
+  const maxLen = opts.maxLength != null ? opts.maxLength : 128;
+  const trimmed = serverId.trim();
+  if (trimmed.length === 0 || trimmed.length > maxLen) return false;
+  if (trimmed.includes('..') || trimmed.includes('/') || trimmed.includes('\\')) return false;
+  return /^[a-zA-Z0-9_.-]+$/.test(trimmed);
+}
+
 /**
  * Проверка на SQL injection паттерны
  * @param {string} str - строка для проверки
@@ -328,6 +344,7 @@ module.exports = {
   isValidASN,
   isValidCommunity,
   isValidGateway,
+  isValidServerId,
   sanitizeString,
   isSafeSQLString,
   isSafeXSSString,
diff --git a/backend/routes/mikrotikBackupRoutes.js b/backend/routes/mikrotikBackupRoutes.js
index 9e516c8..e4bd390 100644
--- a/backend/routes/mikrotikBackupRoutes.js
+++ b/backend/routes/mikrotikBackupRoutes.js
@@ -298,7 +298,7 @@ async function runBackupNow(req, res) {
       comment: 'Manual backup from UI (/api/mikrotik/backups/run)',
     });
 
-    return sendOk(res, {
+    return res.json({
       ok: true,
       key,
       serverId,
diff --git a/backend/routes/mikrotikConfigRoutes.js b/backend/routes/mikrotikConfigRoutes.js
index d7f1bb0..12f8104 100644
--- a/backend/routes/mikrotikConfigRoutes.js
+++ b/backend/routes/mikrotikConfigRoutes.js
@@ -236,7 +236,7 @@ async function testMikrotikConnection(req, res) {
     const client = createRosClient(creds);
     await client.print('system/resource');
 
-    return sendOk(res, { ok: true, message: 'Connection successful' });
+    return res.json({ ok: true, message: 'Connection successful' });
   } catch (error) {
     const msg = error.response?.data?.message || error.message || 'Connection failed';
     const status = error.response?.status;
@@ -1302,12 +1302,18 @@ async function speedTestViaTunnel(req, res) {
  * POST /api/mikrotik/run-script
  * Body: { serverId, script?: string } — по умолчанию script=update_bgp_filter
  */
+const SCRIPT_NAME_REGEX = /^[a-zA-Z0-9_-]{1,64}$/;
+
 async function runScript(req, res) {
   try {
     const { serverId, script = 'update_bgp_filter' } = req.body || {};
     if (!serverId) {
       return sendError(res, 400, 'serverId is required', 'E_BAD_REQUEST');
     }
+    const scriptStr = String(script).trim();
+    if (!SCRIPT_NAME_REGEX.test(scriptStr)) {
+      return sendError(res, 400, 'script: only alphanumeric, underscore, hyphen, max 64 chars', 'E_BAD_REQUEST');
+    }
 
     const servers = await readServersFromS3();
     const server = servers.find(s => (s.id || s.dns || s.ip) === serverId);
@@ -1324,11 +1330,11 @@ async function runScript(req, res) {
     // Сначала находим скрипт по имени, затем запускаем по .id
     const scripts = await client.print('system/script');
     const list = Array.isArray(scripts?.data) ? scripts.data : (scripts?.data ? [scripts.data] : []);
-    const found = list.find(s => (s.name || s['.id']) === script);
-    const scriptId = found ? (found['.id'] || found.name) : script;
+    const found = list.find(s => (s.name || s['.id']) === scriptStr);
+    const scriptId = found ? (found['.id'] || found.name) : scriptStr;
     await client.command('system/script/run', { '.id': scriptId });
 
-    return sendOk(res, { ok: true, message: `Скрипт ${script} запущен` });
+    return res.json({ ok: true, message: `Скрипт ${scriptStr} запущен` });
   } catch (error) {
     const msg = error.response?.data?.message || error.message || 'Ошибка запуска скрипта';
     const status = error.response?.status;
diff --git a/backend/routes/schedulerRoutes.js b/backend/routes/schedulerRoutes.js
index 9aa95e1..ff983d1 100644
--- a/backend/routes/schedulerRoutes.js
+++ b/backend/routes/schedulerRoutes.js
@@ -106,7 +106,7 @@ async function runNetworkMapSchedulerNow(req, res) {
       } catch (_) {}
     });
 
-    return sendOk(res, { message: 'Запуск выполняется в фоне' });
+    return res.json({ ok: true, message: 'Запуск выполняется в фоне' });
   } catch (e) {
     console.error('[scheduler] run-now', e);
     const msg = e?.message || String(e);
@@ -177,7 +177,7 @@ async function runPingServicesSchedulerNow(req, res) {
     refreshPingServicesCache().catch((err) => {
       console.error('[scheduler] ping-services run-now failed', err);
     });
-    return sendOk(res, { message: 'Обновление кеша пинг-сервисов запущено в фоне' });
+    return res.json({ ok: true, message: 'Обновление кеша пинг-сервисов запущено в фоне' });
   } catch (e) {
     console.error('[scheduler] ping-services run-now', e);
     return sendError(res, 500, 'Не удалось запустить', 'E_SCHEDULER');
@@ -237,7 +237,7 @@ async function runUptimeMonitorSchedulerNow(req, res) {
         body: JSON.stringify({ serverId }),
       }).catch((err) => console.warn('[scheduler] uptime check', serverId, err?.message));
     }
-    return sendOk(res, { message: 'Проверки Uptime Monitor запущены в фоне' });
+    return res.json({ ok: true, message: 'Проверки Uptime Monitor запущены в фоне' });
   } catch (e) {
     console.error('[scheduler] uptime-monitor run-now', e);
     return sendError(res, 500, 'Не удалось запустить', 'E_SCHEDULER');
diff --git a/backend/routes/serverConfigsRoutes.js b/backend/routes/serverConfigsRoutes.js
index 4a52243..6d8ce36 100644
--- a/backend/routes/serverConfigsRoutes.js
+++ b/backend/routes/serverConfigsRoutes.js
@@ -10,6 +10,7 @@ const { sendError, sendOk, checkIfNoneMatch } = require('../middleware/errorHand
 const { GetObjectCommand, HeadObjectCommand } = require('@aws-sdk/client-s3');
 const { streamToString } = require('../services/s3Service');
 const { getS3TextWithHeaders, getS3JsonWithHeaders } = require('../utils/s3Helpers');
+const { isValidServerId } = require('../lib/validators');
 
 const S3_KEY = 'servers.json';
 
@@ -143,9 +144,19 @@ const serverConfigsListRoutes = {
   post: postServerConfigsList
 };
 
+function validateServerIdParam(req, res) {
+  const serverId = req.params?.serverId;
+  if (!serverId || !isValidServerId(serverId)) {
+    sendError(res, 400, 'Invalid serverId: only alphanumeric, dot, dash, underscore allowed', 'E_BAD_REQUEST');
+    return null;
+  }
+  return serverId;
+}
+
 // GET /api/server-configs/:serverId (конкретная конфигурация)
 async function getServerConfig(req, res) {
-  const { serverId } = req.params;
+  const serverId = validateServerIdParam(req, res);
+  if (serverId === null) return;
   await getS3TextWithHeaders(
     `filter-manager/config-${serverId}.txt`,
     req,
@@ -159,7 +170,8 @@ async function getServerConfig(req, res) {
 
 // POST /api/server-configs/:serverId (сохранить конфигурацию)
 async function postServerConfig(req, res) {
-  const { serverId } = req.params;
+  const serverId = validateServerIdParam(req, res);
+  if (serverId === null) return;
   const { config } = req.body;
   
   if (!config) {
@@ -177,7 +189,8 @@ async function postServerConfig(req, res) {
 
 // DELETE /api/server-configs/:serverId (удалить только конфигурацию)
 async function deleteServerConfig(req, res) {
-  const { serverId } = req.params;
+  const serverId = validateServerIdParam(req, res);
+  if (serverId === null) return;
   
   try {
     await deleteS3Object(`filter-manager/config-${serverId}.txt`);
@@ -191,7 +204,8 @@ async function deleteServerConfig(req, res) {
 
 // DELETE /api/server-configs/:serverId/complete (удалить конфигурацию и фильтры)
 async function deleteServerComplete(req, res) {
-  const { serverId } = req.params;
+  const serverId = validateServerIdParam(req, res);
+  if (serverId === null) return;
   
   try {
     await Promise.allSettled([
@@ -208,7 +222,8 @@ async function deleteServerComplete(req, res) {
 
 // GET /api/server-filters/:serverId
 async function getServerFilters(req, res) {
-  const { serverId } = req.params;
+  const serverId = validateServerIdParam(req, res);
+  if (serverId === null) return;
   await getS3JsonWithHeaders(
     `filter-manager/server-filters-${serverId}.json`,
     req,
@@ -219,7 +234,8 @@ async function getServerFilters(req, res) {
 
 // POST /api/server-filters/:serverId
 async function postServerFilters(req, res) {
-  const { serverId } = req.params;
+  const serverId = validateServerIdParam(req, res);
+  if (serverId === null) return;
   const { filters } = req.body;
   
   if (!Array.isArray(filters)) {
diff --git a/backend/utils/encryption.js b/backend/utils/encryption.js
index 9e0cf76..b260275 100644
--- a/backend/utils/encryption.js
+++ b/backend/utils/encryption.js
@@ -120,9 +120,7 @@ function decrypt(encryptedText) {
     }
     console.error('Decryption error details:', {
       error: error.message,
-      stack: error.stack,
-      encryptedTextLength: encryptedText.length,
-      encryptedTextPreview: encryptedText.substring(0, 100)
+      encryptedTextLength: encryptedText.length
     });
     throw error;
   }