diff --git a/packages/insomnia-smoke-test/tests/smoke/pre-request-script-features.test.ts b/packages/insomnia-smoke-test/tests/smoke/pre-request-script-features.test.ts
index 4881f96758..2f019807a3 100644
--- a/packages/insomnia-smoke-test/tests/smoke/pre-request-script-features.test.ts
+++ b/packages/insomnia-smoke-test/tests/smoke/pre-request-script-features.test.ts
@@ -1,7 +1,7 @@
 import { Buffer } from 'node:buffer';
 import path from 'node:path';
 
-import { expect } from '@playwright/test';
+import { expect, type Page } from '@playwright/test';
 
 import { getFixturePath, loadFixture } from '../../playwright/paths';
 import { test } from '../../playwright/test';
@@ -682,6 +682,19 @@ test.describe('unhappy paths', () => {
   });
 });
 
+// Race the expected pre-toggle error text against a 200 OK response. Abort immediately on failure instead of waiting for the error locator to time out.
+async function expectBlockedBeforeOk(page: Page, errorText: string) {
+  const errorLocator = page.getByTestId('response-pane').getByText(errorText);
+  const okLocator = page.locator('[data-testid="response-status-tag"]:visible', { hasText: '200 OK' });
+  const testResponseCode = await Promise.race([
+    errorLocator.waitFor({ state: 'visible' }).then(() => 'blocked' as const),
+    okLocator.waitFor({ state: 'visible' }).then(() => 'ok' as const),
+  ]);
+  if (testResponseCode !== 'blocked') {
+    throw new Error(`expected the script to be blocked with "${errorText}", but a 200 OK response arrived first`);
+  }
+}
+
 test.describe('sandbox features', () => {
   test.slow(process.platform === 'darwin' || process.platform === 'win32', 'Slow app start on these platforms');
 
@@ -709,11 +722,7 @@ test.describe('sandbox features', () => {
     await page.evaluate(() => new Promise(resolve => setTimeout(resolve, 150)));
 
     await page.getByTestId('request-pane').getByRole('button', { name: 'Send' }).click();
-
-    // verify blocked-root error
-    await expect
-      .soft(page.getByTestId('response-pane'))
-      .toContainText("The script was blocked because it used 'this'.");
+    await expectBlockedBeforeOk(page, "The script was blocked because it used 'this'.");
 
     // navigate to Settings → Scripting, disable the "Scopes" blocked roots group
     await page.getByTestId('settings-button').click();
@@ -746,11 +755,7 @@ test.describe('sandbox features', () => {
     await page.evaluate(() => new Promise(resolve => setTimeout(resolve, 150)));
 
     await page.getByTestId('request-pane').getByRole('button', { name: 'Send' }).click();
-
-    // verify blocked-property error
-    await expect
-      .soft(page.getByTestId('response-pane'))
-      .toContainText("The script was blocked because it used the property 'prototype'.");
+    await expectBlockedBeforeOk(page, "The script was blocked because it used the property 'prototype'.");
 
     // navigate to Settings → Scripting, disable the "Prototype Mutation" blocked properties group
     await page.getByTestId('settings-button').click();
@@ -786,8 +791,7 @@ test.describe('sandbox features', () => {
 
     // send — Function masked to undefined → V8 uses the identifier name: "Function is not a constructor"
     await page.getByTestId('request-pane').getByRole('button', { name: 'Send' }).click();
-
-    await expect.soft(page.getByTestId('response-pane')).toContainText('Function is not a constructor');
+    await expectBlockedBeforeOk(page, 'Function is not a constructor');
 
     // navigate to Settings → Scripting, disable the "Runtime APIs" mask group
     await page.getByTestId('settings-button').click();
@@ -817,11 +821,7 @@ test.describe('sandbox features', () => {
     await page.evaluate(() => new Promise(resolve => setTimeout(resolve, 150)));
 
     await page.getByTestId('request-pane').getByRole('button', { name: 'Send' }).click();
-
-    // verify blocked-root error
-    await expect
-      .soft(page.getByTestId('response-pane'))
-      .toContainText("The script was blocked because it used 'process'.");
+    await expectBlockedBeforeOk(page, "The script was blocked because it used 'process'.");
 
     // navigate to Settings → Scripting, disable only the "Node.js Internals" BLOCKED ROOTS group.
     await page.getByTestId('settings-button').click();
@@ -842,4 +842,237 @@ test.describe('sandbox features', () => {
       .not.toContainText("The script was blocked because it used 'process'.");
     await expect.soft(page.locator('[data-testid="response-status-tag"]:visible')).toContainText('200 OK');
   });
+
+  // Master sandbox toggle: turning it off disables all static checks.
+  test("master 'Enable script sandbox' toggle", async ({ page }) => {
+    await page.getByLabel('Request Collection').getByTestId('echo pre-request script result').press('Enter');
+
+    await page.getByRole('tab', { name: 'Scripts' }).click();
+    const editor = page.getByTestId('CodeEditor').getByRole('textbox');
+    await editor.fill(`insomnia.environment.set('result', String(this?.x));`);
+    await page.evaluate(() => new Promise(resolve => setTimeout(resolve, 150)));
+
+    await page.getByTestId('request-pane').getByRole('button', { name: 'Send' }).click();
+    await expectBlockedBeforeOk(page, "The script was blocked because it used 'this'.");
+
+    await page.getByTestId('settings-button').click();
+    await page.locator('text=Insomnia Preferences').first().click();
+    await page.getByRole('tab', { name: 'Scripting' }).click();
+
+    const masterSwitch = page.locator(
+      'xpath=//span[normalize-space(text())="Enable script sandbox"]/ancestor::div[contains(@class,"justify-between")][1]//label[@data-react-aria-pressable]',
+    );
+    await masterSwitch.scrollIntoViewIfNeeded();
+    await masterSwitch.click();
+    await expect.soft(masterSwitch).not.toHaveAttribute('data-selected');
+
+    // child toggles become disabled when the master is off
+    const strictSwitch = page.locator(
+      'xpath=//span[normalize-space(text())="use strict"]/ancestor::div[contains(@class,"justify-between")][1]//label[@data-react-aria-pressable]',
+    );
+    await expect.soft(strictSwitch).toHaveAttribute('data-disabled');
+
+    await page.locator('.app').press('Escape');
+
+    await page.getByTestId('request-pane').getByRole('button', { name: 'Send' }).click();
+    await expect
+      .soft(page.getByTestId('response-pane'))
+      .not.toContainText("The script was blocked because it used 'this'.");
+    await expect.soft(page.locator('[data-testid="response-status-tag"]:visible')).toContainText('200 OK');
+  });
+
+  // 'use strict' toggle: strict mode causes assignment to undeclared identifier to throw.
+  test("'use strict' toggle", async ({ page }) => {
+    await page.getByLabel('Request Collection').getByTestId('echo pre-request script result').press('Enter');
+
+    await page.getByRole('tab', { name: 'Scripts' }).click();
+    const editor = page.getByTestId('CodeEditor').getByRole('textbox');
+    await editor.fill(`function f(){ undeclared = 1; return undeclared; } insomnia.environment.set('result', String(f()));`);
+    await page.evaluate(() => new Promise(resolve => setTimeout(resolve, 150)));
+
+    await page.getByTestId('request-pane').getByRole('button', { name: 'Send' }).click();
+    await expectBlockedBeforeOk(page, 'undeclared is not defined');
+
+    await page.getByTestId('settings-button').click();
+    await page.locator('text=Insomnia Preferences').first().click();
+    await page.getByRole('tab', { name: 'Scripting' }).click();
+    const strictSwitch = page.locator(
+      'xpath=//span[normalize-space(text())="use strict"]/ancestor::div[contains(@class,"justify-between")][1]//label[@data-react-aria-pressable]',
+    );
+    await strictSwitch.scrollIntoViewIfNeeded();
+    await strictSwitch.click();
+    await expect.soft(strictSwitch).not.toHaveAttribute('data-selected');
+    await page.locator('.app').press('Escape');
+
+    await page.getByTestId('request-pane').getByRole('button', { name: 'Send' }).click();
+    await expect.soft(page.getByTestId('response-pane')).not.toContainText('undeclared is not defined');
+    await expect.soft(page.locator('[data-testid="response-status-tag"]:visible')).toContainText('200 OK');
+  });
+
+  // 'block unresolvable properties' toggle: dynamic computed access is statically blocked.
+  test("'block unresolvable properties' toggle", async ({ page }) => {
+    await page.getByLabel('Request Collection').getByTestId('echo pre-request script result').press('Enter');
+
+    await page.getByRole('tab', { name: 'Scripts' }).click();
+    const editor = page.getByTestId('CodeEditor').getByRole('textbox');
+    await editor.fill(`const k = 'foo'; const o = { foo: 42 }; insomnia.environment.set('result', String(o[k]));`);
+    await page.evaluate(() => new Promise(resolve => setTimeout(resolve, 150)));
+
+    await page.getByTestId('request-pane').getByRole('button', { name: 'Send' }).click();
+    await expectBlockedBeforeOk(page, 'dynamic computed property access that cannot be statically verified');
+
+    await page.getByTestId('settings-button').click();
+    await page.locator('text=Insomnia Preferences').first().click();
+    await page.getByRole('tab', { name: 'Scripting' }).click();
+    const blockUnresolvableSwitch = page.locator(
+      'xpath=//span[normalize-space(text())="block unresolvable properties"]/ancestor::div[contains(@class,"justify-between")][1]//label[@data-react-aria-pressable]',
+    );
+    await blockUnresolvableSwitch.scrollIntoViewIfNeeded();
+    await blockUnresolvableSwitch.click();
+    await expect.soft(blockUnresolvableSwitch).not.toHaveAttribute('data-selected');
+    await page.locator('.app').press('Escape');
+
+    await page.getByTestId('request-pane').getByRole('button', { name: 'Send' }).click();
+    await expect
+      .soft(page.getByTestId('response-pane'))
+      .not.toContainText('dynamic computed property access that cannot be statically verified');
+    await expect.soft(page.locator('[data-testid="response-status-tag"]:visible')).toContainText('200 OK');
+  });
+
+  // Mask Rules / Async Scheduling group: setImmediate is masked to undefined at runtime.
+  test('Mask Rules / Async Scheduling group', async ({ page }) => {
+    await page.getByLabel('Request Collection').getByTestId('echo pre-request script result').press('Enter');
+
+    await page.getByRole('tab', { name: 'Scripts' }).click();
+    const editor = page.getByTestId('CodeEditor').getByRole('textbox');
+    await editor.fill(`setImmediate(() => {}); insomnia.environment.set('result', 'ok');`);
+    await page.evaluate(() => new Promise(resolve => setTimeout(resolve, 150)));
+
+    await page.getByTestId('request-pane').getByRole('button', { name: 'Send' }).click();
+    await expectBlockedBeforeOk(page, 'setImmediate is not a function');
+
+    await page.getByTestId('settings-button').click();
+    await page.locator('text=Insomnia Preferences').first().click();
+    await page.getByRole('tab', { name: 'Scripting' }).click();
+    const asyncSchedulingSwitch = page.locator(
+      'div:has(> h4:has-text("Async Scheduling")) label[data-react-aria-pressable]',
+    );
+    await asyncSchedulingSwitch.scrollIntoViewIfNeeded();
+    await asyncSchedulingSwitch.click();
+    await expect.soft(asyncSchedulingSwitch).not.toHaveAttribute('data-selected');
+    await page.locator('.app').press('Escape');
+
+    await page.getByTestId('request-pane').getByRole('button', { name: 'Send' }).click();
+    await expect.soft(page.getByTestId('response-pane')).not.toContainText('setImmediate is not a function');
+    await expect.soft(page.locator('[data-testid="response-status-tag"]:visible')).toContainText('200 OK');
+  });
+
+  // Blocked Properties / Stack Inspection group: 'captureStackTrace' is blocked.
+  test('Blocked Properties / Stack Inspection group', async ({ page }) => {
+    await page.getByLabel('Request Collection').getByTestId('echo pre-request script result').press('Enter');
+
+    await page.getByRole('tab', { name: 'Scripts' }).click();
+    const editor = page.getByTestId('CodeEditor').getByRole('textbox');
+    await editor.fill(`insomnia.environment.set('result', String(typeof Error.captureStackTrace));`);
+    await page.evaluate(() => new Promise(resolve => setTimeout(resolve, 150)));
+
+    await page.getByTestId('request-pane').getByRole('button', { name: 'Send' }).click();
+    await expectBlockedBeforeOk(page, "The script was blocked because it used the property 'captureStackTrace'.");
+
+    await page.getByTestId('settings-button').click();
+    await page.locator('text=Insomnia Preferences').first().click();
+    await page.getByRole('tab', { name: 'Scripting' }).click();
+    const stackInspectionSwitch = page.locator(
+      'div:has(> h4:has-text("Stack Inspection")) label[data-react-aria-pressable]',
+    );
+    await stackInspectionSwitch.scrollIntoViewIfNeeded();
+    await stackInspectionSwitch.click();
+    await expect.soft(stackInspectionSwitch).not.toHaveAttribute('data-selected');
+    await page.locator('.app').press('Escape');
+
+    await page.getByTestId('request-pane').getByRole('button', { name: 'Send' }).click();
+    await expect
+      .soft(page.getByTestId('response-pane'))
+      .not.toContainText("The script was blocked because it used the property 'captureStackTrace'.");
+    await expect.soft(page.locator('[data-testid="response-status-tag"]:visible')).toContainText('200 OK');
+  });
+
+  // Blocked Properties / Accessor Helpers group: 'defineProperty' is blocked.
+  test('Blocked Properties / Accessor Helpers group', async ({ page }) => {
+    await page.getByLabel('Request Collection').getByTestId('echo pre-request script result').press('Enter');
+
+    await page.getByRole('tab', { name: 'Scripts' }).click();
+    const editor = page.getByTestId('CodeEditor').getByRole('textbox');
+    await editor.fill(`const o = {}; Object.defineProperty(o, 'a', { value: 1 }); insomnia.environment.set('result', String(o.a));`);
+    await page.evaluate(() => new Promise(resolve => setTimeout(resolve, 150)));
+
+    await page.getByTestId('request-pane').getByRole('button', { name: 'Send' }).click();
+    await expectBlockedBeforeOk(page, "The script was blocked because it used the property 'defineProperty'.");
+
+    await page.getByTestId('settings-button').click();
+    await page.locator('text=Insomnia Preferences').first().click();
+    await page.getByRole('tab', { name: 'Scripting' }).click();
+    const accessorHelpersSwitch = page.locator(
+      'div:has(> h4:has-text("Accessor Helpers")) label[data-react-aria-pressable]',
+    );
+    await accessorHelpersSwitch.scrollIntoViewIfNeeded();
+    await accessorHelpersSwitch.click();
+    await expect.soft(accessorHelpersSwitch).not.toHaveAttribute('data-selected');
+    await page.locator('.app').press('Escape');
+
+    await page.getByTestId('request-pane').getByRole('button', { name: 'Send' }).click();
+    await expect
+      .soft(page.getByTestId('response-pane'))
+      .not.toContainText("The script was blocked because it used the property 'defineProperty'.");
+    await expect.soft(page.locator('[data-testid="response-status-tag"]:visible')).toContainText('200 OK');
+  });
+
+  // Blocked Roots / Global Object Aliases group: 'globalThis' is blocked.
+  test('Blocked Roots / Global Object Aliases group', async ({ page }) => {
+    await page.getByLabel('Request Collection').getByTestId('echo pre-request script result').press('Enter');
+
+    await page.getByRole('tab', { name: 'Scripts' }).click();
+    const editor = page.getByTestId('CodeEditor').getByRole('textbox');
+    await editor.fill(`insomnia.environment.set('result', String(globalThis.Object));`);
+    await page.evaluate(() => new Promise(resolve => setTimeout(resolve, 150)));
+
+    await page.getByTestId('request-pane').getByRole('button', { name: 'Send' }).click();
+    await expectBlockedBeforeOk(page, "The script was blocked because it used 'globalThis'.");
+
+    await page.getByTestId('settings-button').click();
+    await page.locator('text=Insomnia Preferences').first().click();
+    await page.getByRole('tab', { name: 'Scripting' }).click();
+    const globalAliasesSwitch = page.locator(
+      'div:has(> h4:has-text("Global Object Aliases")) label[data-react-aria-pressable]',
+    );
+    await globalAliasesSwitch.scrollIntoViewIfNeeded();
+    await globalAliasesSwitch.click();
+    await expect.soft(globalAliasesSwitch).not.toHaveAttribute('data-selected');
+    await page.locator('.app').press('Escape');
+
+    // Static rule passes, but the mask still resolves `globalThis` to undefined,
+    // so `globalThis.Object` throws — verify we now hit the next security layer.
+    await page.getByTestId('request-pane').getByRole('button', { name: 'Send' }).click();
+    await expect
+      .soft(page.getByTestId('response-pane'))
+      .toContainText("Cannot read properties of undefined (reading 'Object')");
+
+    // Disable the matching mask group so `globalThis` resolves to the real host global.
+    await page.getByTestId('settings-button').click();
+    await page.locator('text=Insomnia Preferences').first().click();
+    await page.getByRole('tab', { name: 'Scripting' }).click();
+    const globalMaskSwitch = page.locator(
+      'div:has(> h4:has-text("Global & Node.js Internals")) label[data-react-aria-pressable]',
+    );
+    await globalMaskSwitch.scrollIntoViewIfNeeded();
+    await globalMaskSwitch.click();
+    await expect.soft(globalMaskSwitch).not.toHaveAttribute('data-selected');
+    await page.locator('.app').press('Escape');
+
+    await page.getByTestId('request-pane').getByRole('button', { name: 'Send' }).click();
+    await expect
+      .soft(page.getByTestId('response-pane'))
+      .not.toContainText("Cannot read properties of undefined (reading 'Object')");
+    await expect.soft(page.locator('[data-testid="response-status-tag"]:visible')).toContainText('200 OK');
+  });
 });
diff --git a/packages/insomnia/src/scripting/sandbox.ts b/packages/insomnia/src/scripting/sandbox.ts
index 6ab1ba9bce..11b9c54009 100644
--- a/packages/insomnia/src/scripting/sandbox.ts
+++ b/packages/insomnia/src/scripting/sandbox.ts
@@ -25,16 +25,13 @@ export interface SandboxContext {
   bridgeOps: BridgeOps;
 }
 
-// Derive the default blocked sets from the canonical rule lists in script-security-policy.
 const SANDBOX_BLOCKED_PROPERTIES = new Set(blockedPropertyRules.map(r => r.name));
 const SANDBOX_BLOCKED_ROOTS = new Set(blockedRootRules.map(r => r.name));
 
-// These interceptor rules always apply — they cannot be disabled via settings and run even when
-// the sandbox is turned off, because they gate access to critical host APIs (require, window, eval).
+// The original (v12.5.0) interceptor rules always apply. 
 const ALWAYS_ON_INTERCEPTORS = new Set(['require', 'window', 'eval']);
 
-// Sentinel returned by getMemberPropertyName when the computed key cannot be statically resolved.
-// Callers must treat this as a hard block — unknown dynamic keys are rejected by policy.
+// AST check operates based on getMemberPropertyName, some keys may not be statically resolved. We can drop all unresolvable properties to resolve this. 
 const UNRESOLVABLE = Symbol('unresolvable');
 
 // Walks a MemberExpression down to its root Identifier.
@@ -44,8 +41,7 @@ function getMemberRoot(node: any): string | null {
   return null;
 }
 
-// Returns MemberExpression property name, or UNRESOLVABLE when the computed key cannot be
-// statically determined (e.g. BinaryExpression, dynamic TemplateLiteral). 
+// Returns MemberExpression property name, or UNRESOLVABLE when the computed key cannot statically determined. 
 function getMemberPropertyName(node: acorn.MemberExpression): string | typeof UNRESOLVABLE | null {
   if (!node.computed && node.property.type === 'Identifier') {
     return (node.property as acorn.Identifier).name;
@@ -392,33 +388,22 @@ export async function prepareSandbox(
     ({ names: maskNames, values: maskValues } = alwaysOnPolicy.buildMaskScope(checkSandboxViolations));
   }
 
-  // Replace the placeholder eval interceptor with one that carries the full parameter mask.
-  // The rule-level interceptor uses (0,eval) (indirect eval in global scope), which bypasses
-  // parameter masking and lets scripts access real globals like require, Function, process.
-  // Here we patch maskValues to use a new AsyncFunction with the same params and a direct eval,
-  // so eval'd code inherits the masked parameter bindings.
+  // Wrap eval so user-supplied source is checked and then evaluated in a scope that inherits the same masked bindings as the outer sandbox.
   const evalIdx = maskNames.indexOf('eval');
   if (evalIdx !== -1) {
-    const strictModeEnabled = context.settings.scriptStrictModeEnabled !== false;
-    const evalBody = strictModeEnabled
-      ? '"use strict"; return eval(__eval_script__);'
-      : 'return eval(__eval_script__);';
-    // Exclude 'eval' from the parameter list: naming a parameter 'eval' is illegal in strict mode,
-    // and the function needs to call the real eval (not the interceptor) for direct-eval scoping.
-    // Use a synchronous Function (not AsyncFunction) to preserve the synchronous return contract —
-    // AsyncFunction always returns a Promise, which breaks postMessage structured-clone for sync scripts.
-    const nonEvalMaskNames = maskNames.filter(n => n !== 'eval');
-    const nonEvalMaskValues = maskValues.filter((_, i) => maskNames[i] !== 'eval');
-    const scopedEvalFn = new Function(
-      ...nonEvalMaskNames, '__eval_script__',
-      evalBody,
-    );
+    const useStrict = context.settings.scriptStrictModeEnabled !== false;
+    const body = `${useStrict ? '"use strict"; ' : ''}return eval(__eval_script__);`;
+    // 'eval' is excluded from params: it's illegal as a strict-mode param name,
+    // and the wrapper must call the real eval for direct-eval scoping to apply.
+    const paramNames = maskNames.filter(n => n !== 'eval');
+    const paramValues = maskValues.filter((_, i) => maskNames[i] !== 'eval');
+    const scopedEvalFn = new Function(...paramNames, '__eval_script__', body);
     maskValues[evalIdx] = (script: string) => {
       if (!script || typeof script !== 'string') {
         throw new Error('eval is called with invalid or empty value');
       }
       evalViolationCheck(script);
-      return scopedEvalFn(...nonEvalMaskValues, script);
+      return scopedEvalFn(...paramValues, script);
     };
   }