diff --git a/src/channels/telegram/monitor.ts b/src/channels/telegram/monitor.ts
index c41f3e6..b172e8a 100644
--- a/src/channels/telegram/monitor.ts
+++ b/src/channels/telegram/monitor.ts
@@ -87,6 +87,12 @@ export async function startTelegramMonitor(opts: TelegramMonitorOptions): Promis
 
   // handle callback queries (approvals + questions)
   bot.on('callback_query:data', async (ctx) => {
+    const callbackSenderId = String(ctx.from?.id || '');
+    if (opts.allowFrom && opts.allowFrom.length > 0 && !opts.allowFrom.includes(callbackSenderId)) {
+      await ctx.answerCallbackQuery('Unauthorized');
+      return;
+    }
+
     const data = ctx.callbackQuery.data;
     const sep = data.indexOf(':');
     if (sep < 0) return;
diff --git a/src/config.ts b/src/config.ts
index f0b168c..57ff6c0 100644
--- a/src/config.ts
+++ b/src/config.ts
@@ -278,19 +278,29 @@ export function isPathAllowed(
   try {
     resolved = realpathSync(targetPath);
   } catch {
-    resolved = resolve(targetPath);
+    // For non-existent targets, resolve the parent via realpath to prevent
+    // symlink-parent bypasses, then append the final segment.
+    const parent = dirname(resolve(targetPath));
+    try {
+      resolved = join(realpathSync(parent), resolve(targetPath).slice(parent.length));
+    } catch {
+      resolved = resolve(targetPath);
+    }
   }
 
+  const pathMatch = (dir: string, target: string) =>
+    target === dir || target.startsWith(dir + '/');
+
   // denied: always_denied + global + channel-specific (all merged)
-  const globalDenied = config.gateway?.deniedPaths || ALWAYS_DENIED;
+  const globalDenied = [...ALWAYS_DENIED, ...(config.gateway?.deniedPaths || [])];
   const channelDenied = channelOverride?.deniedPaths || [];
   const denied = [...globalDenied, ...channelDenied].map(p => resolve(p.replace(/^~/, home)));
-  if (denied.some(d => resolved.startsWith(d))) return false;
+  if (denied.some(d => pathMatch(d, resolved))) return false;
 
   // allowed: channel-specific overrides global if set
   const allowedRaw = channelOverride?.allowedPaths?.length
     ? channelOverride.allowedPaths
     : (config.gateway?.allowedPaths || [home, '/tmp']);
   const allowed = allowedRaw.map(p => resolve(p.replace(/^~/, home)));
-  return allowed.some(a => resolved.startsWith(a));
+  return allowed.some(a => pathMatch(a, resolved));
 }
diff --git a/src/gateway/server.ts b/src/gateway/server.ts
index 0a4a8f6..e2b635e 100644
--- a/src/gateway/server.ts
+++ b/src/gateway/server.ts
@@ -2,7 +2,7 @@ import { WebSocketServer, WebSocket } from 'ws';
 import { createServer } from 'node:http';
 import { readdirSync, statSync, readFileSync, writeFileSync, existsSync, mkdirSync, rmSync, renameSync, chmodSync, unlinkSync, watch, type FSWatcher } from 'node:fs';
 import { writeFile } from 'node:fs/promises';
-import { execSync } from 'node:child_process';
+import { execSync, execFileSync } from 'node:child_process';
 import { resolve as pathResolve, join, dirname } from 'node:path';
 import { homedir } from 'node:os';
 import { createConnection } from 'node:net';
@@ -63,9 +63,7 @@ import {
 
 function macNotify(title: string, body: string) {
   try {
-    const t = title.replace(/"/g, '\\"');
-    const b = body.replace(/"/g, '\\"');
-    execSync(`osascript -e 'display notification "${b}" with title "${t}"'`, { stdio: 'ignore' });
+    execFileSync('osascript', ['-e', `display notification "${body}" with title "${title}"`], { stdio: 'ignore' });
   } catch { /* ignore */ }
 }
 
diff --git a/src/providers/claude.ts b/src/providers/claude.ts
index 03fa6a3..742dc57 100644
--- a/src/providers/claude.ts
+++ b/src/providers/claude.ts
@@ -552,8 +552,8 @@ export class ClaudeProvider implements Provider {
       return { authenticated: false, error: 'Invalid auth code.' };
     }
 
-    if (returnedState && returnedState !== this._pkceState) {
-      console.warn('[claude] OAuth state mismatch, proceeding anyway');
+    if (returnedState !== this._pkceState) {
+      return { authenticated: false, error: 'OAuth state mismatch — possible CSRF. Please retry login.' };
     }
 
     try {
diff --git a/src/skills/loader.ts b/src/skills/loader.ts
index 92d327a..42bca56 100644
--- a/src/skills/loader.ts
+++ b/src/skills/loader.ts
@@ -1,6 +1,6 @@
 import { readFileSync, existsSync, readdirSync, statSync } from 'node:fs';
 import { join, basename, dirname } from 'node:path';
-import { execSync } from 'node:child_process';
+import { execFileSync } from 'node:child_process';
 import matter from 'gray-matter';
 import type { Config } from '../config.js';
 
@@ -28,7 +28,7 @@ export type SkillEligibility = {
 
 function checkBinaryExists(bin: string): boolean {
   try {
-    execSync(`which ${bin}`, { stdio: 'ignore' });
+    execFileSync('which', [bin], { stdio: 'ignore' });
     return true;
   } catch {
     return false;