diff --git a/frontend/__tests__/utils/misc.spec.ts b/frontend/__tests__/utils/misc.spec.ts
index fc0a29781085..893282946e25 100644
--- a/frontend/__tests__/utils/misc.spec.ts
+++ b/frontend/__tests__/utils/misc.spec.ts
@@ -1,5 +1,5 @@
 import { describe, it, expect } from "vitest";
-import { getErrorMessage, isObject } from "../../src/ts/utils/misc";
+import { getErrorMessage, isObject, escapeHTML } from "../../src/ts/utils/misc";
 import {
   getLanguageDisplayString,
   removeLanguageSize,
@@ -123,6 +123,46 @@ describe("misc.ts", () => {
     });
   });
 
+  describe("escapeHTML", () => {
+    it("should escape HTML characters correctly", () => {
+      const tests = [
+        {
+          input: "hello world",
+          expected: "hello world",
+        },
+        {
+          input: "<script>alert('xss')</script>",
+          expected: "&lt;script&gt;alert(&#39;xss&#39;)&lt;&#x2F;script&gt;",
+        },
+        {
+          input: 'Hello "world" & friends',
+          expected: "Hello &quot;world&quot; &amp; friends",
+        },
+        {
+          input: "Click `here` to continue",
+          expected: "Click &#x60;here&#x60; to continue",
+        },
+        {
+          input: null,
+          expected: null,
+        },
+        {
+          input: undefined,
+          expected: undefined,
+        },
+        {
+          input: "",
+          expected: "",
+        },
+      ];
+
+      tests.forEach((test) => {
+        const result = escapeHTML(test.input);
+        expect(result).toBe(test.expected);
+      });
+    });
+  });
+
   describe("getErrorMesssage", () => {
     it("should correctly get the error message", () => {
       const tests = [
diff --git a/frontend/src/ts/elements/input-validation.ts b/frontend/src/ts/elements/input-validation.ts
index 73a595679d28..a1971bd622f8 100644
--- a/frontend/src/ts/elements/input-validation.ts
+++ b/frontend/src/ts/elements/input-validation.ts
@@ -32,9 +32,6 @@ export type Validation<T> = {
 
   /** custom debounce delay for `isValid` call. defaults to 100 */
   debounceDelay?: number;
-
-  /** Resets the value to the current config if empty */
-  resetIfEmpty?: false;
 };
 
 // oxlint-disable-next-line no-explicit-any
@@ -144,8 +141,9 @@ export type ValidationOptions<T> = (T extends string
 };
 
 export type ValidatedHtmlInputElement = HTMLInputElement & {
-  isValid: () => boolean | undefined;
+  getValidationResult: () => ValidationResult;
   setValue: (val: string | null) => void;
+  triggerValidation: () => void;
 };
 /**
  * adds an 'InputIndicator` to the given `inputElement` and updates its status depending on the given validation
@@ -177,9 +175,11 @@ export function validateWithIndicator<T>(
     },
   });
 
-  let isValid: boolean | undefined = undefined;
+  let currentStatus: ValidationResult = {
+    status: "checking",
+  };
   const callback = (result: ValidationResult): void => {
-    isValid = result.status === "success" || result.status === "warning";
+    currentStatus = result;
     if (result.status === "failed" || result.status === "warning") {
       indicator.show(result.status, result.errorMessage);
     } else {
@@ -197,16 +197,20 @@ export function validateWithIndicator<T>(
   inputElement.addEventListener("input", handler);
 
   const result = inputElement as ValidatedHtmlInputElement;
-  result.isValid = () => isValid;
+  result.getValidationResult = () => {
+    return currentStatus;
+  };
   result.setValue = (val: string | null) => {
     inputElement.value = val ?? "";
     if (val === null) {
-      isValid = undefined;
       indicator.hide();
     } else {
       inputElement.dispatchEvent(new Event("input"));
     }
   };
+  result.triggerValidation = () => {
+    inputElement.dispatchEvent(new Event("input"));
+  };
 
   return result;
 }
@@ -223,6 +227,8 @@ export type ConfigInputOptions<K extends ConfigKey, T = ConfigType[K]> = {
     schema: boolean;
     /** optional callback is called for each change of the validation result */
     validationCallback?: (result: ValidationResult) => void;
+    /** Resets the value to the current config if empty */
+    resetIfEmpty?: false;
   };
 };
 
diff --git a/frontend/src/ts/elements/modes-notice.ts b/frontend/src/ts/elements/modes-notice.ts
index ebd21d05e791..aa2888565dcd 100644
--- a/frontend/src/ts/elements/modes-notice.ts
+++ b/frontend/src/ts/elements/modes-notice.ts
@@ -10,6 +10,7 @@ import * as CustomTextState from "../states/custom-text-name";
 import { getLanguageDisplayString } from "../utils/strings";
 import Format from "../utils/format";
 import { getActiveFunboxNames } from "../test/funbox/list";
+import { escapeHTML } from "../utils/misc";
 
 ConfigEvent.subscribe((eventKey) => {
   const configKeys: ConfigEvent.ConfigEventKey[] = [
@@ -79,7 +80,9 @@ export async function update(): Promise<void> {
   const isLong = CustomTextState.isCustomTextLong();
   if (Config.mode === "custom" && customTextName !== "" && isLong) {
     $(".pageTest #testModesNotice").append(
-      `<div class="textButton noInteraction"><i class="fas fa-book"></i>${customTextName} (shift + enter to save progress)</div>`
+      `<div class="textButton noInteraction"><i class="fas fa-book"></i>${escapeHTML(
+        customTextName
+      )} (shift + enter to save progress)</div>`
     );
   }
 
diff --git a/frontend/src/ts/modals/edit-preset.ts b/frontend/src/ts/modals/edit-preset.ts
index 6f9cdd91a117..cf0e6a258c2e 100644
--- a/frontend/src/ts/modals/edit-preset.ts
+++ b/frontend/src/ts/modals/edit-preset.ts
@@ -262,7 +262,7 @@ async function apply(): Promise<void> {
     return;
   }
 
-  if (presetNameEl?.isValid() === false) {
+  if (presetNameEl?.getValidationResult().status === "failed") {
     Notifications.add("Preset name is not valid", 0);
     return;
   }
diff --git a/frontend/src/ts/modals/save-custom-text.ts b/frontend/src/ts/modals/save-custom-text.ts
index d63e77f946f0..6bf9cd8d6ed3 100644
--- a/frontend/src/ts/modals/save-custom-text.ts
+++ b/frontend/src/ts/modals/save-custom-text.ts
@@ -1,11 +1,13 @@
 import * as CustomText from "../test/custom-text";
 import * as Notifications from "../elements/notifications";
 import * as CustomTextState from "../states/custom-text-name";
-import { InputIndicator } from "../elements/input-indicator";
-import { debounce } from "throttle-debounce";
 import AnimatedModal, { ShowOptions } from "../utils/animated-modal";
+import { validateWithIndicator } from "../elements/input-validation";
+import { z } from "zod";
 
-let indicator: InputIndicator | undefined;
+type IncomingData = {
+  text: string[];
+};
 
 type State = {
   textToSave: string[];
@@ -15,6 +17,35 @@ const state: State = {
   textToSave: [],
 };
 
+const validatedInput = validateWithIndicator(
+  $("#saveCustomTextModal .textName")[0] as HTMLInputElement,
+  {
+    debounceDelay: 500,
+    schema: z
+      .string()
+      .min(1)
+      .max(32)
+      .regex(/^[\w\s-]+$/, {
+        message:
+          "Name can only contain letters, numbers, spaces, underscores and hyphens",
+      }),
+    isValid: async (value) => {
+      const checkbox = $("#saveCustomTextModal .isLongText").prop(
+        "checked"
+      ) as boolean;
+      const names = CustomText.getCustomTextNames(checkbox);
+      return !names.includes(value) ? true : "Duplicate name";
+    },
+    callback: (result) => {
+      if (result.status === "success") {
+        $("#saveCustomTextModal button.save").prop("disabled", false);
+      } else {
+        $("#saveCustomTextModal button.save").prop("disabled", true);
+      }
+    },
+  }
+);
+
 export async function show(options: ShowOptions<IncomingData>): Promise<void> {
   state.textToSave = [];
   void modal.show({
@@ -28,10 +59,6 @@ export async function show(options: ShowOptions<IncomingData>): Promise<void> {
   });
 }
 
-function hide(): void {
-  void modal.hide();
-}
-
 function save(): boolean {
   const name = $("#saveCustomTextModal .textName").val() as string;
   const checkbox = $("#saveCustomTextModal .isLongText").prop(
@@ -59,69 +86,18 @@ function save(): boolean {
   }
 }
 
-function updateIndicatorAndButton(): void {
-  const val = $("#saveCustomTextModal .textName").val() as string;
-  const checkbox = $("#saveCustomTextModal .isLongText").prop(
-    "checked"
-  ) as boolean;
-
-  if (!val) {
-    indicator?.hide();
-    $("#saveCustomTextModal button.save").prop("disabled", true);
-  } else {
-    const names = CustomText.getCustomTextNames(checkbox);
-    if (names.includes(val)) {
-      indicator?.show("unavailable");
-      $("#saveCustomTextModal button.save").prop("disabled", true);
-    } else {
-      indicator?.show("available");
-      $("#saveCustomTextModal button.save").prop("disabled", false);
-    }
-  }
-}
-
-const updateInputAndButtonDebounced = debounce(500, updateIndicatorAndButton);
-
 async function setup(modalEl: HTMLElement): Promise<void> {
-  indicator = new InputIndicator($("#saveCustomTextModal .textName"), {
-    available: {
-      icon: "fa-check",
-      level: 1,
-    },
-    unavailable: {
-      icon: "fa-times",
-      level: -1,
-    },
-    loading: {
-      icon: "fa-circle-notch",
-      spinIcon: true,
-      level: 0,
-    },
-  });
   modalEl.addEventListener("submit", (e) => {
     e.preventDefault();
-    if (save()) hide();
-  });
-  modalEl.querySelector(".textName")?.addEventListener("input", (e) => {
-    const val = (e.target as HTMLInputElement).value;
-    if (val.length > 0) {
-      indicator?.show("loading");
-      updateInputAndButtonDebounced();
+    if (validatedInput.getValidationResult().status === "success" && save()) {
+      void modal.hide();
     }
   });
   modalEl.querySelector(".isLongText")?.addEventListener("input", (e) => {
-    const val = (e.target as HTMLInputElement).value;
-    if (val.length > 0) {
-      indicator?.show("loading");
-      updateInputAndButtonDebounced();
-    }
+    validatedInput.triggerValidation();
   });
 }
 
-type IncomingData = {
-  text: string[];
-};
-
 const modal = new AnimatedModal<IncomingData>({
   dialogId: "saveCustomTextModal",
   setup,
diff --git a/frontend/src/ts/pages/about.ts b/frontend/src/ts/pages/about.ts
index 9f1c880c9414..0656a87f913e 100644
--- a/frontend/src/ts/pages/about.ts
+++ b/frontend/src/ts/pages/about.ts
@@ -151,7 +151,7 @@ async function fill(): Promise<void> {
   const supportersEl = document.querySelector(".pageAbout .supporters");
   let supportersHTML = "";
   for (const supporter of supporters ?? []) {
-    supportersHTML += `<div>${supporter}</div>`;
+    supportersHTML += `<div>${Misc.escapeHTML(supporter)}</div>`;
   }
   if (supportersEl) {
     supportersEl.innerHTML = supportersHTML;
@@ -160,7 +160,7 @@ async function fill(): Promise<void> {
   const contributorsEl = document.querySelector(".pageAbout .contributors");
   let contributorsHTML = "";
   for (const contributor of contributors ?? []) {
-    contributorsHTML += `<div>${contributor}</div>`;
+    contributorsHTML += `<div>${Misc.escapeHTML(contributor)}</div>`;
   }
   if (contributorsEl) {
     contributorsEl.innerHTML = contributorsHTML;
diff --git a/frontend/src/ts/pages/login.ts b/frontend/src/ts/pages/login.ts
index 632b6f5944fc..715c9c4d4a85 100644
--- a/frontend/src/ts/pages/login.ts
+++ b/frontend/src/ts/pages/login.ts
@@ -170,7 +170,8 @@ validateWithIndicator(emailVerifyInputEl, {
   debounceDelay: 0,
   callback: (result) => {
     registerForm.email =
-      emailInputEl.isValid() && result.status === "success"
+      emailInputEl.getValidationResult().status === "success" &&
+      result.status === "success"
         ? emailInputEl.value
         : undefined;
     updateSignupButton();
@@ -204,7 +205,8 @@ validateWithIndicator(passwordVerifyInputEl, {
   debounceDelay: 0,
   callback: (result) => {
     registerForm.password =
-      passwordInputEl.isValid() && result.status === "success"
+      passwordInputEl.getValidationResult().status === "success" &&
+      result.status === "success"
         ? passwordInputEl.value
         : undefined;
     updateSignupButton();
diff --git a/frontend/src/ts/utils/misc.ts b/frontend/src/ts/utils/misc.ts
index 976cf5d7da0d..5920e7694d2a 100644
--- a/frontend/src/ts/utils/misc.ts
+++ b/frontend/src/ts/utils/misc.ts
@@ -164,18 +164,22 @@ export function escapeRegExp(str: string): string {
   return str.replace(/[.*+?^${}()|[\]\\]/g, "\\$&");
 }
 
-export function escapeHTML(str: string): string {
+export function escapeHTML<T extends string | null | undefined>(str: T): T {
   if (str === null || str === undefined) {
     return str;
   }
-  str = str
-    .replace(/&/g, "&amp;")
-    .replace(/</g, "&lt;")
-    .replace(/>/g, "&gt;")
-    .replace(/"/g, "&quot;")
-    .replace(/'/g, "&#039;");
-
-  return str;
+
+  const escapeMap: Record<string, string> = {
+    "&": "&amp;",
+    "<": "&lt;",
+    ">": "&gt;",
+    '"': "&quot;",
+    "'": "&#39;",
+    "/": "&#x2F;",
+    "`": "&#x60;",
+  };
+
+  return str.replace(/[&<>"'/`]/g, (char) => escapeMap[char] as string) as T;
 }
 
 export function isUsernameValid(name: string): boolean {