diff --git a/changelog.d/fixes/tailscale-port-and-windows-path.md b/changelog.d/fixes/tailscale-port-and-windows-path.md
new file mode 100644
index 0000000000..0becdaa9c3
--- /dev/null
+++ b/changelog.d/fixes/tailscale-port-and-windows-path.md
@@ -0,0 +1 @@
+- Fixed Tailscale tunnel setup to reject ports outside the valid 1-65535 range and safely install Windows MSI packages from paths containing apostrophes.
diff --git a/src/app/api/tunnels/tailscale/routeUtils.ts b/src/app/api/tunnels/tailscale/routeUtils.ts
index 131005bcbb..b6df5118e5 100644
--- a/src/app/api/tunnels/tailscale/routeUtils.ts
+++ b/src/app/api/tunnels/tailscale/routeUtils.ts
@@ -6,7 +6,7 @@ import { isValidationFailure, validateBody } from "@/shared/validation/helpers";
 export const tailscaleEnableSchema = z.object({
   sudoPassword: z.string().optional(),
   hostname: z.string().optional(),
-  port: z.number().int().positive().optional(),
+  port: z.number().int().min(1).max(65535).optional(),
 });
 
 export const tailscaleLoginSchema = z.object({
diff --git a/src/lib/tailscaleTunnel.ts b/src/lib/tailscaleTunnel.ts
index e98e2f0fc6..1db4d9b1ca 100644
--- a/src/lib/tailscaleTunnel.ts
+++ b/src/lib/tailscaleTunnel.ts
@@ -1104,6 +1104,11 @@ async function installTailscaleLinux(password: string, onProgress?: (message: st
   });
 }
 
+export function buildWindowsTailscaleInstallCommand(msiPath: string): string {
+  const escapedMsiPath = msiPath.replace(/'/g, "''");
+  return `Start-Process msiexec -ArgumentList '/i','${escapedMsiPath}','TS_NOLAUNCH=true','/quiet','/norestart' -Verb RunAs -Wait`;
+}
+
 async function installTailscaleWindows(onProgress?: (message: string) => void) {
   const msiUrl = "https://pkgs.tailscale.com/stable/tailscale-setup-latest-amd64.msi";
   const msiPath = path.join(os.tmpdir(), "tailscale-setup.msi");
@@ -1125,12 +1130,7 @@ async function installTailscaleWindows(onProgress?: (message: string) => void) {
   await new Promise<void>((resolve, reject) => {
     const child = spawn(
       "powershell",
-      [
-        "-NoProfile",
-        "-NonInteractive",
-        "-Command",
-        `Start-Process msiexec -ArgumentList '/i','${msiPath}','TS_NOLAUNCH=true','/quiet','/norestart' -Verb RunAs -Wait`,
-      ],
+      ["-NoProfile", "-NonInteractive", "-Command", buildWindowsTailscaleInstallCommand(msiPath)],
       {
         windowsHide: true,
         stdio: ["ignore", "pipe", "pipe"],
diff --git a/tests/unit/tailscale-validation.test.ts b/tests/unit/tailscale-validation.test.ts
new file mode 100644
index 0000000000..baed8ef6ae
--- /dev/null
+++ b/tests/unit/tailscale-validation.test.ts
@@ -0,0 +1,19 @@
+import assert from "node:assert/strict";
+import test from "node:test";
+
+import { tailscaleEnableSchema } from "../../src/app/api/tunnels/tailscale/routeUtils.ts";
+import { buildWindowsTailscaleInstallCommand } from "../../src/lib/tailscaleTunnel.ts";
+
+test("tailscale enable accepts only valid TCP ports", () => {
+  assert.equal(tailscaleEnableSchema.safeParse({ port: 1 }).success, true);
+  assert.equal(tailscaleEnableSchema.safeParse({ port: 65535 }).success, true);
+  assert.equal(tailscaleEnableSchema.safeParse({ port: 0 }).success, false);
+  assert.equal(tailscaleEnableSchema.safeParse({ port: 65536 }).success, false);
+});
+
+test("Windows installer command escapes apostrophes in MSI paths", () => {
+  assert.equal(
+    buildWindowsTailscaleInstallCommand("C:\\Users\\O'Brien\\tailscale-setup.msi"),
+    "Start-Process msiexec -ArgumentList '/i','C:\\Users\\O''Brien\\tailscale-setup.msi','TS_NOLAUNCH=true','/quiet','/norestart' -Verb RunAs -Wait"
+  );
+});