diff --git a/app/api/v1/tokens/route.ts b/app/api/v1/tokens/route.ts
index c3a6111f..651b671f 100644
--- a/app/api/v1/tokens/route.ts
+++ b/app/api/v1/tokens/route.ts
@@ -30,7 +30,10 @@ export async function POST(request: NextRequest) {
     try {
       result = await createApiToken(body.name, userId, body.expires_at ?? undefined);
     } catch (e) {
-      if (e instanceof Error && (e.message.includes("expires_at") || e.message.includes("ISO 8601"))) {
+      if (e instanceof Error && (
+        e.message.includes("expires_at") || e.message.includes("ISO 8601") ||
+        e.message.includes("characters or fewer") || e.message.includes("Maximum of")
+      )) {
         return NextResponse.json({ error: e.message }, { status: 400 });
       }
       throw e;
diff --git a/next.config.mjs b/next.config.mjs
index 0cbd1dfb..843d443b 100644
--- a/next.config.mjs
+++ b/next.config.mjs
@@ -20,6 +20,7 @@ const nextConfig = {
     }
   },
   output: 'standalone',
+  poweredByHeader: false,
   // Security headers (CSP, etc.) are set per-request in proxy.ts middleware
   // with a unique nonce, so they are NOT defined here as static headers.
 };
diff --git a/src/lib/api-auth.ts b/src/lib/api-auth.ts
index 30ee7c91..7551f5b0 100644
--- a/src/lib/api-auth.ts
+++ b/src/lib/api-auth.ts
@@ -11,6 +11,13 @@ export class ApiAuthError extends Error {
   }
 }
 
+export class NotFoundError extends Error {
+  constructor(message: string) {
+    super(message);
+    this.name = "NotFoundError";
+  }
+}
+
 export type ApiAuthResult = {
   userId: number;
   role: string;
@@ -91,6 +98,12 @@ export function apiErrorResponse(error: unknown): NextResponse {
   if (error instanceof ApiAuthError) {
     return NextResponse.json({ error: error.message }, { status: error.status });
   }
+  if (error instanceof NotFoundError) {
+    return NextResponse.json({ error: error.message }, { status: 404 });
+  }
+  if (error instanceof Error && error.message.toLowerCase().includes("not found")) {
+    return NextResponse.json({ error: error.message }, { status: 404 });
+  }
   return NextResponse.json(
     { error: error instanceof Error ? error.message : "Internal server error" },
     { status: 500 }
diff --git a/src/lib/auth.ts b/src/lib/auth.ts
index 32cd1566..bbeb03fd 100644
--- a/src/lib/auth.ts
+++ b/src/lib/auth.ts
@@ -322,7 +322,7 @@ export const { handlers, signIn, signOut, auth } = NextAuth({
           throw new Error(`LINKING_REQUIRED:${linkingId}`);
         }
 
-        // New OAuth user - create account (defaults to admin role)
+        // New OAuth user - create account
         const newUser = await createUser({
           email: user.email,
           name: user.name,
diff --git a/src/lib/models/api-tokens.ts b/src/lib/models/api-tokens.ts
index 04715aea..782c47b4 100644
--- a/src/lib/models/api-tokens.ts
+++ b/src/lib/models/api-tokens.ts
@@ -1,7 +1,8 @@
 import { createHash, randomBytes } from "node:crypto";
 import db, { nowIso, toIso } from "../db";
 import { apiTokens } from "../db/schema";
-import { eq } from "drizzle-orm";
+import { count, eq } from "drizzle-orm";
+import { NotFoundError } from "../api-auth";
 
 export type ApiToken = {
   id: number;
@@ -29,11 +30,28 @@ function hashToken(rawToken: string): string {
   return createHash("sha256").update(rawToken).digest("hex");
 }
 
+const MAX_TOKENS_PER_USER = 10;
+const MAX_TOKEN_NAME_LENGTH = 100;
+
 export async function createApiToken(
   name: string,
   createdBy: number,
   expiresAt?: string
 ): Promise<{ token: ApiToken; rawToken: string }> {
+  const trimmedName = name.trim();
+  if (trimmedName.length > MAX_TOKEN_NAME_LENGTH) {
+    throw new Error(`Token name must be ${MAX_TOKEN_NAME_LENGTH} characters or fewer`);
+  }
+
+  // Enforce per-user token limit
+  const existingCount = await db
+    .select({ value: count() })
+    .from(apiTokens)
+    .where(eq(apiTokens.createdBy, createdBy));
+  if (existingCount[0] && existingCount[0].value >= MAX_TOKENS_PER_USER) {
+    throw new Error(`Maximum of ${MAX_TOKENS_PER_USER} API tokens per user`);
+  }
+
   // Validate expires_at is a valid ISO 8601 date in the future
   let validatedExpiresAt: string | null = null;
   if (expiresAt) {
@@ -91,7 +109,7 @@ export async function deleteApiToken(id: number, userId: number): Promise<void>
   });
 
   if (!token) {
-    throw new Error("Token not found");
+    throw new NotFoundError("Token not found");
   }
 
   // Check if the user owns the token or is an admin
diff --git a/src/lib/models/proxy-hosts.ts b/src/lib/models/proxy-hosts.ts
index 46f5c87c..e7fc91b3 100644
--- a/src/lib/models/proxy-hosts.ts
+++ b/src/lib/models/proxy-hosts.ts
@@ -6,6 +6,19 @@ import { asc, desc, eq, count, like, or } from "drizzle-orm";
 import { type GeoBlockSettings } from "../settings";
 import { normalizeProxyHostDomains } from "../proxy-host-domains";
 
+function validateUpstreamProtocol(upstream: string): void {
+  const trimmed = upstream.trim();
+  if (!trimmed) return;
+  // If upstream contains "://", enforce http or https scheme
+  const schemeMatch = trimmed.match(/^([a-zA-Z][a-zA-Z0-9+.-]*):\/\//);
+  if (schemeMatch) {
+    const scheme = schemeMatch[1].toLowerCase();
+    if (scheme !== "http" && scheme !== "https") {
+      throw new Error(`Invalid upstream protocol "${scheme}://". Only http:// and https:// are allowed`);
+    }
+  }
+}
+
 const DEFAULT_AUTHENTIK_HEADERS = [
   "X-Authentik-Username",
   "X-Authentik-Groups",
@@ -1608,6 +1621,7 @@ export async function createProxyHost(input: ProxyHostInput, actorUserId: number
   if (!input.upstreams || input.upstreams.length === 0) {
     throw new Error("At least one upstream must be specified");
   }
+  input.upstreams.forEach(validateUpstreamProtocol);
 
   const now = nowIso();
   const meta = buildMeta({}, input);
@@ -1666,6 +1680,9 @@ export async function updateProxyHost(id: number, input: Partial<ProxyHostInput>
   const domains = JSON.stringify(
     input.domains ? normalizeProxyHostDomains(input.domains) : existing.domains
   );
+  if (input.upstreams) {
+    input.upstreams.forEach(validateUpstreamProtocol);
+  }
   const upstreams = input.upstreams ? JSON.stringify(Array.from(new Set(input.upstreams))) : JSON.stringify(existing.upstreams);
   const existingMeta: ProxyHostMeta = {
     custom_reverse_proxy_json: existing.custom_reverse_proxy_json ?? undefined,