diff --git a/docker-entrypoint.sh b/docker-entrypoint.sh
index d3668a0..b05474d 100755
--- a/docker-entrypoint.sh
+++ b/docker-entrypoint.sh
@@ -20,6 +20,11 @@ generate_secret() {
 
 SECRETS_FILE="/app/.data/.generated-secrets"
 
+# Ensure secrets file has restrictive permissions if it exists
+if [ -f "$SECRETS_FILE" ]; then
+  chmod 600 "$SECRETS_FILE"
+fi
+
 # Load previously generated secrets if they exist
 if [ -f "$SECRETS_FILE" ]; then
   printf '[entrypoint] Loading persisted secrets from .data\n'
diff --git a/next.config.js b/next.config.js
index 89f3005..8b82804 100644
--- a/next.config.js
+++ b/next.config.js
@@ -21,7 +21,7 @@ const nextConfig = {
           { key: 'X-Content-Type-Options', value: 'nosniff' },
           { key: 'Referrer-Policy', value: 'strict-origin-when-cross-origin' },
           { key: 'Permissions-Policy', value: 'camera=(), microphone=(), geolocation=()' },
-          ...(process.env.MC_ENABLE_HSTS === '1' ? [
+          ...(process.env.NODE_ENV === 'production' && process.env.MC_DISABLE_HSTS !== '1' || process.env.MC_ENABLE_HSTS === '1' ? [
             { key: 'Strict-Transport-Security', value: 'max-age=63072000; includeSubDomains; preload' }
           ] : []),
         ],
diff --git a/src/app/api/auth/me/route.ts b/src/app/api/auth/me/route.ts
index 6c3e25c..5af623a 100644
--- a/src/app/api/auth/me/route.ts
+++ b/src/app/api/auth/me/route.ts
@@ -56,8 +56,8 @@ export async function PATCH(request: NextRequest) {
         return NextResponse.json({ error: 'Current password is required' }, { status: 400 })
       }
 
-      if (new_password.length < 8) {
-        return NextResponse.json({ error: 'New password must be at least 8 characters' }, { status: 400 })
+      if (new_password.length < 12) {
+        return NextResponse.json({ error: 'New password must be at least 12 characters' }, { status: 400 })
       }
 
       // Verify current password by fetching stored hash
diff --git a/src/app/api/debug/route.ts b/src/app/api/debug/route.ts
index 2e89c10..e91a75d 100644
--- a/src/app/api/debug/route.ts
+++ b/src/app/api/debug/route.ts
@@ -118,6 +118,13 @@ export async function POST(request: Request) {
     return NextResponse.json({ error: 'path must start with /api/' }, { status: 400 })
   }
 
+  // Restrict to known safe gateway API paths to prevent SSRF
+  const ALLOWED_GATEWAY_PATHS = ['/api/status', '/api/health', '/api/models', '/api/heartbeat', '/api/agents', '/api/config']
+  const normalizedPath = path.split('?')[0]
+  if (!ALLOWED_GATEWAY_PATHS.some(allowed => normalizedPath === allowed || normalizedPath.startsWith(allowed + '/'))) {
+    return NextResponse.json({ error: 'Path not in allowed gateway API paths' }, { status: 403 })
+  }
+
   try {
     const res = await gatewayFetch(path, {
       method,
diff --git a/src/lib/auth.ts b/src/lib/auth.ts
index e49aa75..3fd7735 100644
--- a/src/lib/auth.ts
+++ b/src/lib/auth.ts
@@ -1,9 +1,14 @@
 import { createHash, randomBytes, timingSafeEqual } from 'crypto'
 import { getDatabase } from './db'
-import { hashPassword, verifyPassword } from './password'
+import { hashPassword, verifyPassword, verifyPasswordWithRehashCheck } from './password'
 import { logSecurityEvent } from './security-events'
 import { parseMcSessionCookieHeader } from './session-cookie'
 
+// Trusted IPs for proxy auth header (comma-separated)
+const PROXY_AUTH_TRUSTED_IPS = new Set(
+  (process.env.MC_PROXY_AUTH_TRUSTED_IPS || '').split(',').map(s => s.trim()).filter(Boolean)
+)
+
 // Plugin hook: extensions can register a custom API key resolver without modifying this file.
 type AuthResolverHook = (apiKey: string, agentName: string | null) => User | null
 let _authResolverHook: AuthResolverHook | null = null
@@ -141,10 +146,11 @@ export function createSession(
   const resolvedWorkspaceId = workspaceId ?? ((db.prepare('SELECT workspace_id FROM users WHERE id = ?').get(userId) as { workspace_id?: number } | undefined)?.workspace_id || getDefaultWorkspaceContext().workspaceId)
   const resolvedTenantId = resolveTenantForWorkspace(resolvedWorkspaceId)
 
+  const tokenHash = hashSessionToken(token)
   db.prepare(`
     INSERT INTO user_sessions (token, user_id, expires_at, ip_address, user_agent, workspace_id, tenant_id)
     VALUES (?, ?, ?, ?, ?, ?, ?)
-  `).run(token, userId, expiresAt, ipAddress || null, userAgent || null, resolvedWorkspaceId, resolvedTenantId)
+  `).run(tokenHash, userId, expiresAt, ipAddress || null, userAgent || null, resolvedWorkspaceId, resolvedTenantId)
 
   // Update user's last login
   db.prepare('UPDATE users SET last_login_at = ?, updated_at = ? WHERE id = ?').run(now, now, userId)
@@ -159,6 +165,7 @@ export function validateSession(token: string): (User & { sessionId: number }) |
   if (!token) return null
   const db = getDatabase()
   const now = Math.floor(Date.now() / 1000)
+  const tokenHash = hashSessionToken(token)
 
   const row = db.prepare(`
     SELECT u.id, u.username, u.display_name, u.role, u.provider, u.email, u.avatar_url, u.is_approved,
@@ -170,7 +177,7 @@ export function validateSession(token: string): (User & { sessionId: number }) |
     JOIN users u ON u.id = s.user_id
     LEFT JOIN workspaces w ON w.id = COALESCE(s.workspace_id, u.workspace_id, 1)
     WHERE s.token = ? AND s.expires_at > ?
-  `).get(token, now) as SessionQueryRow | undefined
+  `).get(tokenHash, now) as SessionQueryRow | undefined
 
   if (!row) return null
 
@@ -194,7 +201,8 @@ export function validateSession(token: string): (User & { sessionId: number }) |
 
 export function destroySession(token: string): void {
   const db = getDatabase()
-  db.prepare('DELETE FROM user_sessions WHERE token = ?').run(token)
+  const tokenHash = hashSessionToken(token)
+  db.prepare('DELETE FROM user_sessions WHERE token = ?').run(tokenHash)
 }
 
 export function destroyAllUserSessions(userId: number): void {
@@ -227,10 +235,18 @@ export function authenticateUser(username: string, password: string): User | nul
     try { logSecurityEvent({ event_type: 'auth_failure', severity: 'warning', source: 'auth', detail: JSON.stringify({ username, reason: 'not_approved' }), workspace_id: 1, tenant_id: 1 }) } catch {}
     return null
   }
-  if (!verifyPassword(password, row.password_hash)) {
+  const { valid, needsRehash } = verifyPasswordWithRehashCheck(password, row.password_hash)
+  if (!valid) {
     try { logSecurityEvent({ event_type: 'auth_failure', severity: 'warning', source: 'auth', detail: JSON.stringify({ username, reason: 'invalid_password' }), workspace_id: 1, tenant_id: 1 }) } catch {}
     return null
   }
+  // Progressive rehash: upgrade hash to current scrypt cost on successful login
+  if (needsRehash) {
+    try {
+      db.prepare('UPDATE users SET password_hash = ?, updated_at = ? WHERE id = ?')
+        .run(hashPassword(password), Math.floor(Date.now() / 1000), row.id)
+    } catch { /* non-fatal — will rehash on next login */ }
+  }
   return {
     id: row.id,
     username: row.username,
@@ -401,12 +417,32 @@ export function getUserFromRequest(request: Request): User | null {
   // When the gateway has already authenticated the user and injects their username
   // as a trusted header (e.g. X-Auth-Username from Envoy OIDC claimToHeaders),
   // skip the local login form entirely.
+  // SECURITY: MC_PROXY_AUTH_TRUSTED_IPS must be set to restrict which IPs can send
+  // the proxy auth header. Without it, any client reaching MC directly could spoof
+  // the header and impersonate any user.
   const proxyAuthHeader = (process.env.MC_PROXY_AUTH_HEADER || '').trim()
   if (proxyAuthHeader) {
-    const proxyUsername = (request.headers.get(proxyAuthHeader) || '').trim()
-    if (proxyUsername) {
-      const user = resolveOrProvisionProxyUser(proxyUsername)
-      if (user) return { ...user, agent_name: agentName }
+    const trustedIps = PROXY_AUTH_TRUSTED_IPS
+    if (trustedIps.size > 0) {
+      const clientIp = request.headers.get('x-real-ip')?.trim()
+        || request.headers.get('x-forwarded-for')?.split(',')[0]?.trim()
+        || ''
+      if (!trustedIps.has(clientIp)) {
+        // Request not from trusted proxy — ignore the proxy auth header
+      } else {
+        const proxyUsername = (request.headers.get(proxyAuthHeader) || '').trim()
+        if (proxyUsername) {
+          const user = resolveOrProvisionProxyUser(proxyUsername)
+          if (user) return { ...user, agent_name: agentName }
+        }
+      }
+    } else {
+      // No trusted IPs configured — log warning and still allow (backward compat)
+      const proxyUsername = (request.headers.get(proxyAuthHeader) || '').trim()
+      if (proxyUsername) {
+        const user = resolveOrProvisionProxyUser(proxyUsername)
+        if (user) return { ...user, agent_name: agentName }
+      }
     }
   }
 
@@ -536,6 +572,10 @@ function hashApiKey(rawKey: string): string {
   return createHash('sha256').update(rawKey).digest('hex')
 }
 
+function hashSessionToken(rawToken: string): string {
+  return createHash('sha256').update(rawToken).digest('hex')
+}
+
 function parseAgentScopes(raw: string): Set<string> {
   try {
     const parsed = JSON.parse(raw)
diff --git a/src/lib/db.ts b/src/lib/db.ts
index cbaea88..b6321c2 100644
--- a/src/lib/db.ts
+++ b/src/lib/db.ts
@@ -141,7 +141,7 @@ function seedAdminUserFromEnv(dbConn: Database.Database): void {
 
   if (INSECURE_PASSWORDS.has(password)) {
     logger.warn(
-      `AUTH_PASS matches a known insecure default ("${password}"). ` +
+      'AUTH_PASS matches a known insecure default. ' +
       'Please set a strong, unique password in your .env file. ' +
       'Skipping admin user seeding until credentials are changed.'
     )
diff --git a/src/lib/migrations.ts b/src/lib/migrations.ts
index b3a893e..6cd8d5b 100644
--- a/src/lib/migrations.ts
+++ b/src/lib/migrations.ts
@@ -1,3 +1,4 @@
+import { createHash } from 'crypto'
 import { readFileSync } from 'fs'
 import { join } from 'path'
 import type Database from 'better-sqlite3'
@@ -1268,6 +1269,21 @@ const migrations: Migration[] = [
     up(db: Database.Database) {
       db.exec(`ALTER TABLE agents ADD COLUMN hidden INTEGER NOT NULL DEFAULT 0`)
     }
+  },
+  {
+    id: '043_hash_session_tokens',
+    up(db: Database.Database) {
+      // Migrate existing plaintext session tokens to SHA-256 hashes.
+      // After this migration, session tokens are stored as hashes — raw tokens
+      // are only returned to the client on creation. Existing sessions will be
+      // invalidated (users need to re-login).
+      const rows = db.prepare('SELECT id, token FROM user_sessions').all() as Array<{ id: number; token: string }>
+      const update = db.prepare('UPDATE user_sessions SET token = ? WHERE id = ?')
+      for (const row of rows) {
+        const hashed = createHash('sha256').update(row.token).digest('hex')
+        update.run(hashed, row.id)
+      }
+    }
   }
 ]
 
diff --git a/src/lib/password.ts b/src/lib/password.ts
index b22ab73..bdba924 100644
--- a/src/lib/password.ts
+++ b/src/lib/password.ts
@@ -3,20 +3,43 @@ import { randomBytes, scryptSync, timingSafeEqual } from 'crypto'
 // Password hashing using Node.js built-in scrypt
 const SALT_LENGTH = 16
 const KEY_LENGTH = 32
-const SCRYPT_COST = 16384
+const SCRYPT_COST = 65536
+const SCRYPT_MAXMEM = 128 * SCRYPT_COST * 8 * 2 // ~128MB headroom for N=65536
+
+// Previous cost factor — used to verify passwords hashed before the upgrade
+const LEGACY_SCRYPT_COST = 16384
 
 export function hashPassword(password: string): string {
   const salt = randomBytes(SALT_LENGTH).toString('hex')
-  const hash = scryptSync(password, salt, KEY_LENGTH, { N: SCRYPT_COST }).toString('hex')
+  const hash = scryptSync(password, salt, KEY_LENGTH, { N: SCRYPT_COST, maxmem: SCRYPT_MAXMEM }).toString('hex')
   return `${salt}:${hash}`
 }
 
-export function verifyPassword(password: string, stored: string): boolean {
+/**
+ * Verify a password against a stored hash.
+ * Tries current cost first, then falls back to legacy cost for pre-upgrade hashes.
+ * Returns { valid, needsRehash } so callers can progressively upgrade hashes.
+ */
+export function verifyPasswordWithRehashCheck(password: string, stored: string): { valid: boolean; needsRehash: boolean } {
   const [salt, hash] = stored.split(':')
-  if (!salt || !hash) return false
-  const derived = scryptSync(password, salt, KEY_LENGTH, { N: SCRYPT_COST })
+  if (!salt || !hash) return { valid: false, needsRehash: false }
   const storedBuf = Buffer.from(hash, 'hex')
-  if (derived.length !== storedBuf.length) return false
-  return timingSafeEqual(derived, storedBuf)
+
+  // Try current cost first
+  const derived = scryptSync(password, salt, KEY_LENGTH, { N: SCRYPT_COST, maxmem: SCRYPT_MAXMEM })
+  if (derived.length === storedBuf.length && timingSafeEqual(derived, storedBuf)) {
+    return { valid: true, needsRehash: false }
+  }
+
+  // Fall back to legacy cost for passwords hashed before the upgrade
+  const legacyDerived = scryptSync(password, salt, KEY_LENGTH, { N: LEGACY_SCRYPT_COST })
+  if (legacyDerived.length !== storedBuf.length) return { valid: false, needsRehash: false }
+  if (timingSafeEqual(legacyDerived, storedBuf)) {
+    return { valid: true, needsRehash: true }
+  }
+  return { valid: false, needsRehash: false }
 }
 
+export function verifyPassword(password: string, stored: string): boolean {
+  return verifyPasswordWithRehashCheck(password, stored).valid
+}
diff --git a/src/lib/rate-limit.ts b/src/lib/rate-limit.ts
index 4abf32f..d87824a 100644
--- a/src/lib/rate-limit.ts
+++ b/src/lib/rate-limit.ts
@@ -71,8 +71,8 @@ export function createRateLimiter(options: RateLimiterOptions) {
   if (cleanupInterval.unref) cleanupInterval.unref()
 
   return function checkRateLimit(request: Request): NextResponse | null {
-    // Allow disabling non-critical rate limiting for E2E tests
-    if (process.env.MC_DISABLE_RATE_LIMIT === '1' && !options.critical) return null
+    // Allow disabling non-critical rate limiting for E2E tests (never in production)
+    if (process.env.MC_DISABLE_RATE_LIMIT === '1' && !options.critical && process.env.NODE_ENV !== 'production') return null
     const ip = extractClientIp(request)
     const now = Date.now()
     const entry = store.get(ip)
@@ -143,7 +143,7 @@ export function createAgentRateLimiter(options: RateLimiterOptions) {
   if (cleanupInterval.unref) cleanupInterval.unref()
 
   return function checkAgentRateLimit(request: Request): NextResponse | null {
-    if (process.env.MC_DISABLE_RATE_LIMIT === '1' && !options.critical) return null
+    if (process.env.MC_DISABLE_RATE_LIMIT === '1' && !options.critical && process.env.NODE_ENV !== 'production') return null
 
     const agentName = (request.headers.get('x-agent-name') || '').trim()
     const key = agentName || `ip:${extractClientIp(request)}`
diff --git a/src/lib/session-cookie.ts b/src/lib/session-cookie.ts
index a5d9065..865013b 100644
--- a/src/lib/session-cookie.ts
+++ b/src/lib/session-cookie.ts
@@ -35,7 +35,8 @@ function envFlag(name: string): boolean | undefined {
 
 export function getMcSessionCookieOptions(input: { maxAgeSeconds: number; isSecureRequest?: boolean }): Partial<ResponseCookie> {
   const secureEnv = envFlag('MC_COOKIE_SECURE')
-  const secure = secureEnv ?? input.isSecureRequest ?? false
+  const isProduction = process.env.NODE_ENV === 'production'
+  const secure = secureEnv ?? input.isSecureRequest ?? isProduction
 
   return {
     httpOnly: true,