diff --git a/.gitignore b/.gitignore
index a39720b..2c166b8 100644
--- a/.gitignore
+++ b/.gitignore
@@ -34,6 +34,9 @@ yarn-error.log*
 .env*
 !.env.example
 
+# First-run admin credentials written by the seed (0600). Never commit.
+.first-admin-credentials
+
 # vercel
 .vercel
 
diff --git a/__tests__/email-escape.test.ts b/__tests__/email-escape.test.ts
new file mode 100644
index 0000000..90347ef
--- /dev/null
+++ b/__tests__/email-escape.test.ts
@@ -0,0 +1,69 @@
+// __tests__/email-escape.test.ts
+import { describe, it, expect } from "vitest";
+import { escapeHtml } from "@/server/email/escape";
+import { ticketReplyHtml, ticketConfirmationHtml } from "@/server/email/templates/ticket";
+import { appointmentConfirmationHtml } from "@/server/email/templates/appointment";
+
+describe("escapeHtml", () => {
+  it("neutralizes every HTML-significant character", () => {
+    expect(escapeHtml(`<script>alert("x")&'`)).toBe(
+      "&lt;script&gt;alert(&quot;x&quot;)&amp;&#39;"
+    );
+  });
+
+  it("leaves ordinary text untouched", () => {
+    expect(escapeHtml("Goetch Stone")).toBe("Goetch Stone");
+  });
+
+  it("escapes & before entity-encoding so it can't be double-decoded", () => {
+    // "&lt;" in input must become "&amp;lt;", not stay "&lt;".
+    expect(escapeHtml("&lt;")).toBe("&amp;lt;");
+  });
+});
+
+// The whole point of the change: attacker-controlled fields must not reach the
+// recipient's inbox as live markup. These assert the payload is neutralized in
+// the actual rendered templates, not just in the helper.
+describe("email templates escape injected markup", () => {
+  const payload = `<img src=x onerror=alert(1)>`;
+
+  it("ticket reply body (reaches staff) is escaped", () => {
+    const html = ticketReplyHtml({
+      ticketNumber: "TKT-1",
+      subject: payload,
+      submitterName: payload,
+      replyBody: payload,
+      replierName: "Staff",
+      trackUrl: "https://akritos.com/support/track?token=abc",
+      companyName: "Akritos",
+    });
+    expect(html).not.toContain("<img src=x onerror=alert(1)>");
+    expect(html).toContain("&lt;img src=x onerror=alert(1)&gt;");
+  });
+
+  it("ticket confirmation subject/name are escaped", () => {
+    const html = ticketConfirmationHtml({
+      ticketNumber: "TKT-1",
+      subject: payload,
+      submitterName: payload,
+      trackUrl: "https://akritos.com/x",
+      companyName: "Akritos",
+    });
+    expect(html).not.toContain("<img src=x");
+  });
+
+  it("appointment confirmation name/service/notes are escaped", () => {
+    const html = appointmentConfirmationHtml({
+      serviceName: payload,
+      bookerName: payload,
+      startsAt: new Date("2026-07-01T15:00:00Z"),
+      duration: 30,
+      timezone: "America/New_York",
+      cancelUrl: "https://akritos.com/book/cancel?token=abc",
+      companyName: "Akritos",
+      notes: payload,
+    });
+    expect(html).not.toContain("<img src=x");
+    expect(html).toContain("&lt;img src=x");
+  });
+});
diff --git a/app/api/tickets/reply/route.ts b/app/api/tickets/reply/route.ts
index 10d57e2..1aeebd7 100644
--- a/app/api/tickets/reply/route.ts
+++ b/app/api/tickets/reply/route.ts
@@ -4,6 +4,7 @@ import { NextRequest, NextResponse } from "next/server";
 import { db } from "@/server/db";
 import { rateLimit } from "@/server/rate-limit";
 import { sendEmail } from "@/server/email";
+import { escapeHtml } from "@/server/email/escape";
 
 export async function POST(request: NextRequest) {
   const ip = request.headers.get("x-forwarded-for") ?? "unknown";
@@ -85,7 +86,7 @@ export async function POST(request: NextRequest) {
     sendEmail({
       to: ticket.assignedTo.email,
       subject: `[${ticket.ticketNumber}] Client replied: ${ticket.subject}`,
-      html: `<p>${textBody.replace(/\n/g, "<br />")}</p>`,
+      html: `<p>${escapeHtml(textBody).replace(/\n/g, "<br />")}</p>`,
       text: textBody,
     }).catch(() => {});
   }
diff --git a/app/privacy/page.tsx b/app/privacy/page.tsx
index cb603e0..fe179f6 100644
--- a/app/privacy/page.tsx
+++ b/app/privacy/page.tsx
@@ -90,9 +90,8 @@ export default function PrivacyPage() {
           </Section>
 
           <Section title="How we protect your information">
-            All data is transmitted over HTTPS. Application data is stored in
-            encrypted databases. API keys and credentials are encrypted at rest
-            using AES-256-GCM. Access to client data is restricted to
+            All data is transmitted over HTTPS. Our database is not exposed to
+            the public internet, and access to client data is restricted to
             authorized team members only.
           </Section>
 
diff --git a/components/auth/login-form.tsx b/components/auth/login-form.tsx
index 4a1363f..3ed851e 100644
--- a/components/auth/login-form.tsx
+++ b/components/auth/login-form.tsx
@@ -12,7 +12,15 @@ import { Label } from "@/components/ui/label";
 export function LoginForm() {
   const router = useRouter();
   const searchParams = useSearchParams();
-  const callbackUrl = searchParams.get("callbackUrl") ?? "/dashboard";
+  // Only allow same-origin relative paths — a full/protocol-relative URL here
+  // would be an open redirect (a user who just authenticated on the real page
+  // gets bounced to an attacker's site). `//evil.com` is protocol-relative, so
+  // reject anything that doesn't start with a single "/".
+  const rawCallback = searchParams.get("callbackUrl");
+  const callbackUrl =
+    rawCallback && rawCallback.startsWith("/") && !rawCallback.startsWith("//")
+      ? rawCallback
+      : "/dashboard";
 
   const [email, setEmail] = useState("");
   const [password, setPassword] = useState("");
diff --git a/deploy.sh b/deploy.sh
index 79df4a5..a6cf81c 100755
--- a/deploy.sh
+++ b/deploy.sh
@@ -70,7 +70,13 @@ SERVICE_COUNT=$($COMPOSE exec -T db \
   psql -U simplerms -d simplerms -tAc "SELECT COUNT(*) FROM \"Service\";" 2>/dev/null || echo "0")
 if [ "${USER_COUNT// /}" = "0" ] || [ "${SERVICE_COUNT// /}" = "0" ]; then
   echo "==> Seeding database (users: ${USER_COUNT// /}, services: ${SERVICE_COUNT// /})"
-  $COMPOSE run --rm migrator npx prisma db seed
+  # Mount the repo dir so the seed's first-admin credentials file (written 0600)
+  # lands on the host instead of vanishing with the ephemeral container — and so
+  # the generated password never has to be echoed to the deploy log.
+  rm -f "$REPO_DIR/.first-admin-credentials"
+  $COMPOSE run --rm -T -v "$REPO_DIR:/host-out" \
+    -e SEED_ADMIN_CRED_FILE=/host-out/.first-admin-credentials \
+    migrator npx prisma db seed
 else
   echo "    Database already seeded (${USER_COUNT// /} users, ${SERVICE_COUNT// /} services)"
 fi
@@ -219,19 +225,17 @@ PUBLIC_URL=$(grep -E '^NEXT_PUBLIC_APP_URL=' .env.local 2>/dev/null | cut -d= -f
 echo " ${PUBLIC_URL:-http://$(curl -sf ifconfig.me 2>/dev/null || echo 'YOUR_IP')}"
 echo ""
 
-# If the seed generated a fresh admin password, surface the credentials file path.
-# The file lives inside the migrator container; copy it to the host for the operator.
+# The seed writes fresh first-run admin credentials to this host-mounted 0600
+# file (see the seed step above). Surface only the path — never the password.
 CRED_HOST_PATH="$REPO_DIR/.first-admin-credentials"
-if $COMPOSE --profile tools run --rm -T migrator test -f /app/.first-admin-credentials 2>/dev/null; then
-  $COMPOSE --profile tools run --rm -T migrator cat /app/.first-admin-credentials > "$CRED_HOST_PATH" 2>/dev/null
-  chmod 600 "$CRED_HOST_PATH"
+if [ -f "$CRED_HOST_PATH" ]; then
+  chmod 600 "$CRED_HOST_PATH" 2>/dev/null || true
   echo " FIRST-RUN ADMIN CREDENTIALS:"
   echo "   $CRED_HOST_PATH"
-  echo "   (mode 0600 — read once, change password, then delete)"
+  echo "   (mode 0600 — read once, change the password in Settings, then delete)"
   echo ""
   echo "   cat $CRED_HOST_PATH"
 else
-  echo " Admin already exists. To reset password:"
-  echo "   docker compose --profile tools run --rm migrator npx tsx scripts/reset-admin-password.ts"
+  echo " No new admin credentials generated this deploy (admin already exists)."
 fi
 echo "============================================"
diff --git a/package-lock.json b/package-lock.json
index 24a265a..1def85e 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -2117,9 +2117,6 @@
       "cpu": [
         "arm64"
       ],
-      "libc": [
-        "glibc"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -2136,9 +2133,6 @@
       "cpu": [
         "arm64"
       ],
-      "libc": [
-        "musl"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -2155,9 +2149,6 @@
       "cpu": [
         "x64"
       ],
-      "libc": [
-        "glibc"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -2174,9 +2165,6 @@
       "cpu": [
         "x64"
       ],
-      "libc": [
-        "musl"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -2685,9 +2673,6 @@
         "arm64"
       ],
       "dev": true,
-      "libc": [
-        "glibc"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -2705,9 +2690,6 @@
         "arm64"
       ],
       "dev": true,
-      "libc": [
-        "musl"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -2725,9 +2707,6 @@
         "ppc64"
       ],
       "dev": true,
-      "libc": [
-        "glibc"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -2745,9 +2724,6 @@
         "s390x"
       ],
       "dev": true,
-      "libc": [
-        "glibc"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -2765,9 +2741,6 @@
         "x64"
       ],
       "dev": true,
-      "libc": [
-        "glibc"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -2785,9 +2758,6 @@
         "x64"
       ],
       "dev": true,
-      "libc": [
-        "musl"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -3066,9 +3036,6 @@
         "arm64"
       ],
       "dev": true,
-      "libc": [
-        "glibc"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -3086,9 +3053,6 @@
         "arm64"
       ],
       "dev": true,
-      "libc": [
-        "musl"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -3106,9 +3070,6 @@
         "x64"
       ],
       "dev": true,
-      "libc": [
-        "glibc"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -3126,9 +3087,6 @@
         "x64"
       ],
       "dev": true,
-      "libc": [
-        "musl"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -4692,20 +4650,20 @@
       }
     },
     "node_modules/body-parser": {
-      "version": "2.2.2",
-      "resolved": "https://registry.npmjs.org/body-parser/-/body-parser-2.2.2.tgz",
-      "integrity": "sha512-oP5VkATKlNwcgvxi0vM0p/D3n2C3EReYVX+DNYs5TjZFn/oQt2j+4sVJtSMr18pdRr8wjTcBl6LoV+FUwzPmNA==",
+      "version": "2.3.0",
+      "resolved": "https://registry.npmjs.org/body-parser/-/body-parser-2.3.0.tgz",
+      "integrity": "sha512-2cGmJupaNgg+QUwVLAucDuWuoMZ6EX9iHDRswZ5lsNYEmwPaRknMPCLZz07yTzVq/83p4o/wzbDZbBrTvGGTIw==",
       "license": "MIT",
       "dependencies": {
         "bytes": "^3.1.2",
-        "content-type": "^1.0.5",
+        "content-type": "^2.0.0",
         "debug": "^4.4.3",
-        "http-errors": "^2.0.0",
-        "iconv-lite": "^0.7.0",
+        "http-errors": "^2.0.1",
+        "iconv-lite": "^0.7.2",
         "on-finished": "^2.4.1",
-        "qs": "^6.14.1",
-        "raw-body": "^3.0.1",
-        "type-is": "^2.0.1"
+        "qs": "^6.15.2",
+        "raw-body": "^3.0.2",
+        "type-is": "^2.1.0"
       },
       "engines": {
         "node": ">=18"
@@ -4715,10 +4673,23 @@
         "url": "https://opencollective.com/express"
       }
     },
+    "node_modules/body-parser/node_modules/content-type": {
+      "version": "2.0.0",
+      "resolved": "https://registry.npmjs.org/content-type/-/content-type-2.0.0.tgz",
+      "integrity": "sha512-j/O/d7GcZCyNl7/hwZAb606rzqkyvaDctLmckbxLzHvFBzTJHuGEdodATcP3yIRoDrLHkIATJuvzbFlp/ki2cQ==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=18"
+      },
+      "funding": {
+        "type": "opencollective",
+        "url": "https://opencollective.com/express"
+      }
+    },
     "node_modules/brace-expansion": {
-      "version": "5.0.6",
-      "resolved": "https://registry.npmjs.org/brace-expansion/-/brace-expansion-5.0.6.tgz",
-      "integrity": "sha512-kLpxurY4Z4r9sgMsyG0Z9uzsBlgiU/EFKhj/h91/8yHu0edo7XuixOIH3VcJ8kkxs6/jPzoI6U9Vj3WqbMQ94g==",
+      "version": "5.0.7",
+      "resolved": "https://registry.npmjs.org/brace-expansion/-/brace-expansion-5.0.7.tgz",
+      "integrity": "sha512-7oFy703dxfY3/NLxC1fh2SUCQ0H9rmAY+5EpDVfXjUTTs+HEwR2nYaqLv+GWcTsumwxPfiz6CzCNkwXwBUwqCA==",
       "license": "MIT",
       "dependencies": {
         "balanced-match": "^4.0.2"
@@ -7960,9 +7931,9 @@
       "license": "MIT"
     },
     "node_modules/js-yaml": {
-      "version": "4.2.0",
-      "resolved": "https://registry.npmjs.org/js-yaml/-/js-yaml-4.2.0.tgz",
-      "integrity": "sha512-ePWsvanv0DWuDRsW8dnt+R4jQ31SCRCQ7hhNcPXZPsoBZiemuZNYGf7adZdqX2D86j6rvKp3RpCxVTSb8WQlOw==",
+      "version": "4.3.0",
+      "resolved": "https://registry.npmjs.org/js-yaml/-/js-yaml-4.3.0.tgz",
+      "integrity": "sha512-1td788aAnnZ5qs7V2QIRl1owjtYpbKt749Y3xauqQgwIIGF/xXWz1wMTEBx5O3LK3lXLVuqXPdPxj2BoFHaW9Q==",
       "funding": [
         {
           "type": "github",
@@ -8774,18 +8745,18 @@
       }
     },
     "node_modules/next-auth": {
-      "version": "5.0.0-beta.31",
-      "resolved": "https://registry.npmjs.org/next-auth/-/next-auth-5.0.0-beta.31.tgz",
-      "integrity": "sha512-1OBgCKPzo+S7UWWMp3xgvGvIJ0OpV7B3vR4ZDRqD9a4Ch+OT6dakLXG9ivhtmIWVa71nTSXattOHyCg8sNi8/Q==",
+      "version": "5.0.0-beta.32",
+      "resolved": "https://registry.npmjs.org/next-auth/-/next-auth-5.0.0-beta.32.tgz",
+      "integrity": "sha512-CGlChIEWZ6LltNVxrE5yiySMID+Idpmry47JYA5lLwgD8Sx02a8M65VL0TWVz9nbnOioS/tCW/rP/0+mE7Qp4Q==",
       "license": "ISC",
       "dependencies": {
-        "@auth/core": "0.41.2"
+        "@auth/core": "0.41.3"
       },
       "peerDependencies": {
         "@simplewebauthn/browser": "^9.0.1",
         "@simplewebauthn/server": "^9.0.2",
         "next": "^14.0.0-0 || ^15.0.0 || ^16.0.0",
-        "nodemailer": "^7.0.7",
+        "nodemailer": "^7.0.7 || ^8.0.5",
         "react": "^18.2.0 || ^19.0.0"
       },
       "peerDependenciesMeta": {
@@ -8800,6 +8771,35 @@
         }
       }
     },
+    "node_modules/next-auth/node_modules/@auth/core": {
+      "version": "0.41.3",
+      "resolved": "https://registry.npmjs.org/@auth/core/-/core-0.41.3.tgz",
+      "integrity": "sha512-sJ3JMHHkXMD3aOjopv7mOBTO1Ocw4b0fAEXJBz6k7YHLpYQI6C40jCUPc5fNvUKxXRXNE1/sRISA15UrwWJBTw==",
+      "license": "ISC",
+      "dependencies": {
+        "@panva/hkdf": "^1.2.1",
+        "jose": "^6.0.6",
+        "oauth4webapi": "^3.3.0",
+        "preact": "10.24.3",
+        "preact-render-to-string": "6.5.11"
+      },
+      "peerDependencies": {
+        "@simplewebauthn/browser": "^9.0.1",
+        "@simplewebauthn/server": "^9.0.2",
+        "nodemailer": "^7.0.7 || ^8.0.5"
+      },
+      "peerDependenciesMeta": {
+        "@simplewebauthn/browser": {
+          "optional": true
+        },
+        "@simplewebauthn/server": {
+          "optional": true
+        },
+        "nodemailer": {
+          "optional": true
+        }
+      }
+    },
     "node_modules/next/node_modules/postcss": {
       "version": "8.4.31",
       "resolved": "https://registry.npmjs.org/postcss/-/postcss-8.4.31.tgz",
@@ -11148,17 +11148,34 @@
       }
     },
     "node_modules/type-is": {
-      "version": "2.0.1",
-      "resolved": "https://registry.npmjs.org/type-is/-/type-is-2.0.1.tgz",
-      "integrity": "sha512-OZs6gsjF4vMp32qrCbiVSkrFmXtG/AZhY3t0iAMrMBiAZyV9oALtXO8hsrHbMXF9x6L3grlFuwW2oAz7cav+Gw==",
+      "version": "2.1.0",
+      "resolved": "https://registry.npmjs.org/type-is/-/type-is-2.1.0.tgz",
+      "integrity": "sha512-faYHw0anBbc/kWF3zFTEnxSFOAGUX9GFbOBthvDdLsIlEoWOFOtS0zgCiQYwIskL9iGXZL3kAXD8OoZ4GmMATA==",
       "license": "MIT",
       "dependencies": {
-        "content-type": "^1.0.5",
+        "content-type": "^2.0.0",
         "media-typer": "^1.1.0",
         "mime-types": "^3.0.0"
       },
       "engines": {
-        "node": ">= 0.6"
+        "node": ">= 18"
+      },
+      "funding": {
+        "type": "opencollective",
+        "url": "https://opencollective.com/express"
+      }
+    },
+    "node_modules/type-is/node_modules/content-type": {
+      "version": "2.0.0",
+      "resolved": "https://registry.npmjs.org/content-type/-/content-type-2.0.0.tgz",
+      "integrity": "sha512-j/O/d7GcZCyNl7/hwZAb606rzqkyvaDctLmckbxLzHvFBzTJHuGEdodATcP3yIRoDrLHkIATJuvzbFlp/ki2cQ==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=18"
+      },
+      "funding": {
+        "type": "opencollective",
+        "url": "https://opencollective.com/express"
       }
     },
     "node_modules/typed-array-buffer": {
diff --git a/prisma/seed.ts b/prisma/seed.ts
index 4526e6e..7d5a8f4 100644
--- a/prisma/seed.ts
+++ b/prisma/seed.ts
@@ -2,6 +2,7 @@
 import { PrismaClient } from "@prisma/client";
 import bcrypt from "bcryptjs";
 import { randomInt } from "crypto";
+import { writeFileSync } from "node:fs";
 
 const db = new PrismaClient();
 
@@ -36,15 +37,16 @@ async function main() {
     });
 
     if (!explicitPassword) {
-      // Generated password — print on stdout with parseable markers so deploy.sh
-      // can extract and write to a host-side credentials file (the migrator container
-      // is ephemeral, so the file would be lost if written inside).
-      console.log("AKRITOS_FIRST_ADMIN_BEGIN");
-      console.log(`email=${adminEmail}`);
-      console.log(`password=${password}`);
-      console.log("AKRITOS_FIRST_ADMIN_END");
+      // Never print the generated password to stdout — the seed runs in a
+      // container during deploy, and stdout lands in the deploy log. Write it to
+      // a 0600 file instead (a host-mounted path in deploy via SEED_ADMIN_CRED_FILE;
+      // cwd locally) and print only a non-secret pointer.
+      const credFile = process.env.SEED_ADMIN_CRED_FILE ?? ".first-admin-credentials";
+      writeFileSync(credFile, `email=${adminEmail}\npassword=${password}\n`, { mode: 0o600 });
+      console.log(`First admin created. Credentials written to ${credFile} (mode 0600).`);
+      console.log("Read it once, sign in, change the password in Settings, then delete the file.");
     } else {
-      console.log(`Admin created with explicit SEED_ADMIN_PASSWORD: ${adminEmail}`);
+      console.log(`Admin created with SEED_ADMIN_PASSWORD: ${adminEmail}`);
     }
   } else {
     console.log(`Admin exists, skipping: ${existing.email}`);
diff --git a/server/email/escape.ts b/server/email/escape.ts
new file mode 100644
index 0000000..5a6b891
--- /dev/null
+++ b/server/email/escape.ts
@@ -0,0 +1,17 @@
+// server/email/escape.ts
+// Escape a user-supplied value before interpolating it into email HTML. Email
+// bodies are built with template strings, so nothing escapes for us the way
+// React does in the UI — every user-derived value placed into an HTML template
+// (names, subjects, notes, message bodies, even the settings-driven company
+// name) must pass through here. Otherwise an attacker who controls that value
+// injects markup into a recipient's inbox, sent from our authenticated domain
+// (phishing links, tracking pixels, spoofed content). Plain-text bodies don't
+// need this; only the HTML path.
+export function escapeHtml(value: string): string {
+  return value
+    .replace(/&/g, "&amp;")
+    .replace(/</g, "&lt;")
+    .replace(/>/g, "&gt;")
+    .replace(/"/g, "&quot;")
+    .replace(/'/g, "&#39;");
+}
diff --git a/server/email/templates/appointment-reminder.ts b/server/email/templates/appointment-reminder.ts
index 9125b02..a8ab6c5 100644
--- a/server/email/templates/appointment-reminder.ts
+++ b/server/email/templates/appointment-reminder.ts
@@ -1,5 +1,6 @@
 // server/email/templates/appointment-reminder.ts
 import { formatDate } from "@/lib/utils";
+import { escapeHtml } from "@/server/email/escape";
 
 export interface AppointmentReminderData {
   serviceName: string;
@@ -19,7 +20,10 @@ function formatTime(date: Date, tz: string): string {
 }
 
 export function appointmentReminderHtml(data: AppointmentReminderData): string {
-  const { serviceName, bookerName, startsAt, timezone, cancelUrl, companyName } = data;
+  const { startsAt, timezone, cancelUrl } = data;
+  const serviceName = escapeHtml(data.serviceName);
+  const bookerName = escapeHtml(data.bookerName);
+  const companyName = escapeHtml(data.companyName);
 
   return `<!DOCTYPE html>
 <html>
diff --git a/server/email/templates/appointment.ts b/server/email/templates/appointment.ts
index b86aff2..ac814d7 100644
--- a/server/email/templates/appointment.ts
+++ b/server/email/templates/appointment.ts
@@ -1,5 +1,6 @@
 // server/email/templates/appointment.ts
 import { formatDate } from "@/lib/utils";
+import { escapeHtml } from "@/server/email/escape";
 
 export interface AppointmentConfirmationData {
   serviceName: string;
@@ -21,7 +22,10 @@ function formatTime(date: Date, tz: string): string {
 }
 
 export function appointmentConfirmationHtml(data: AppointmentConfirmationData): string {
-  const { serviceName, bookerName, startsAt, duration, timezone, cancelUrl, companyName, notes } = data;
+  const { startsAt, duration, timezone, cancelUrl, notes } = data;
+  const serviceName = escapeHtml(data.serviceName);
+  const bookerName = escapeHtml(data.bookerName);
+  const companyName = escapeHtml(data.companyName);
 
   return `<!DOCTYPE html>
 <html>
@@ -82,7 +86,7 @@ export function appointmentConfirmationHtml(data: AppointmentConfirmationData):
                 </tr>
               </table>
 
-              ${notes ? `<p style="margin:0 0 32px;font-size:13px;color:#6b7280;padding:12px;background:#f3f4f6;border-radius:6px;">Note: ${notes.replace(/&/g, "&amp;").replace(/</g, "&lt;")}</p>` : ""}
+              ${notes ? `<p style="margin:0 0 32px;font-size:13px;color:#6b7280;padding:12px;background:#f3f4f6;border-radius:6px;">Note: ${escapeHtml(notes)}</p>` : ""}
 
               <p style="margin:0;font-size:13px;color:#9ca3af;text-align:center;">
                 Need to cancel? <a href="${cancelUrl}" style="color:#6b7280;">Cancel this appointment</a>
@@ -132,7 +136,10 @@ export interface AppointmentCancellationData {
 }
 
 export function appointmentCancellationHtml(data: AppointmentCancellationData): string {
-  const { serviceName, bookerName, startsAt, timezone, bookUrl, companyName } = data;
+  const { startsAt, timezone, bookUrl } = data;
+  const serviceName = escapeHtml(data.serviceName);
+  const bookerName = escapeHtml(data.bookerName);
+  const companyName = escapeHtml(data.companyName);
 
   return `<!DOCTYPE html>
 <html>
diff --git a/server/email/templates/invoice.ts b/server/email/templates/invoice.ts
index 8baeec4..92d0daf 100644
--- a/server/email/templates/invoice.ts
+++ b/server/email/templates/invoice.ts
@@ -1,5 +1,6 @@
 // server/email/templates/invoice.ts
 import { formatCurrency, formatDate } from "@/lib/utils";
+import { escapeHtml } from "@/server/email/escape";
 
 export interface InvoiceEmailData {
   invoiceNumber: string;
@@ -14,7 +15,10 @@ export interface InvoiceEmailData {
 }
 
 export function invoiceEmailHtml(data: InvoiceEmailData): string {
-  const { invoiceNumber, clientName, issueDate, dueDate, total, currency, paymentLink, portalUrl, companyName } = data;
+  const { issueDate, dueDate, total, currency, paymentLink, portalUrl } = data;
+  const invoiceNumber = escapeHtml(data.invoiceNumber);
+  const clientName = escapeHtml(data.clientName);
+  const companyName = escapeHtml(data.companyName);
 
   return `<!DOCTYPE html>
 <html>
diff --git a/server/email/templates/ticket.ts b/server/email/templates/ticket.ts
index 17a00a6..7024403 100644
--- a/server/email/templates/ticket.ts
+++ b/server/email/templates/ticket.ts
@@ -1,4 +1,5 @@
 // server/email/templates/ticket.ts
+import { escapeHtml } from "@/server/email/escape";
 
 export interface TicketConfirmationData {
   ticketNumber: string;
@@ -9,7 +10,11 @@ export interface TicketConfirmationData {
 }
 
 export function ticketConfirmationHtml(data: TicketConfirmationData): string {
-  const { ticketNumber, subject, submitterName, trackUrl, companyName } = data;
+  const { trackUrl } = data;
+  const ticketNumber = escapeHtml(data.ticketNumber);
+  const subject = escapeHtml(data.subject);
+  const submitterName = escapeHtml(data.submitterName);
+  const companyName = escapeHtml(data.companyName);
 
   return `<!DOCTYPE html>
 <html>
@@ -92,9 +97,13 @@ export interface TicketReplyData {
 }
 
 export function ticketReplyHtml(data: TicketReplyData): string {
-  const { ticketNumber, subject, submitterName, replyBody, replierName, trackUrl, companyName } = data;
-  // Escape HTML in the reply body to prevent injection.
-  const safeBody = replyBody.replace(/&/g, "&amp;").replace(/</g, "&lt;").replace(/>/g, "&gt;").replace(/\n/g, "<br />");
+  const { trackUrl } = data;
+  const ticketNumber = escapeHtml(data.ticketNumber);
+  const subject = escapeHtml(data.subject);
+  const submitterName = escapeHtml(data.submitterName);
+  const replierName = escapeHtml(data.replierName);
+  const companyName = escapeHtml(data.companyName);
+  const safeBody = escapeHtml(data.replyBody).replace(/\n/g, "<br />");
 
   return `<!DOCTYPE html>
 <html>
diff --git a/server/trpc/routers/leads.ts b/server/trpc/routers/leads.ts
index 3687577..e6a15e2 100644
--- a/server/trpc/routers/leads.ts
+++ b/server/trpc/routers/leads.ts
@@ -7,6 +7,7 @@ import { createHmac } from "crypto";
 import { createTRPCRouter, publicProcedure, adminProcedure } from "@/server/trpc/trpc";
 import { rateLimit } from "@/server/rate-limit";
 import { sendEmail } from "@/server/email";
+import { escapeHtml } from "@/server/email/escape";
 
 const SUBMIT_LIMIT = 3;
 const SUBMIT_WINDOW_MS = 60 * 60 * 1000;
@@ -116,8 +117,8 @@ export const leadsRouter = createTRPCRouter({
         "",
         "— Akritos",
       ].join("\n"),
-      html: `<p>${input.name ? `Hi ${input.name.split(" ")[0]},` : "Hi,"}</p>
-<p>Thanks for grabbing ${magnet.what}. Here's the download:</p>
+      html: `<p>${input.name ? `Hi ${escapeHtml(input.name.split(" ")[0]!)},` : "Hi,"}</p>
+<p>Thanks for grabbing ${escapeHtml(magnet.what)}. Here's the download:</p>
 <p><a href="${downloadUrl}">${downloadUrl}</a></p>
 <p>Work through it at your own pace. If you have questions or want a 30-minute walkthrough together — no pitch, no pressure — you can <a href="https://akritos.com/book">book one here</a>.</p>
 <p>— Akritos</p>`,