diff --git a/keepassxc-browser/_locales/en/messages.json b/keepassxc-browser/_locales/en/messages.json
index 3dc65dd..2a0780d 100644
--- a/keepassxc-browser/_locales/en/messages.json
+++ b/keepassxc-browser/_locales/en/messages.json
@@ -387,6 +387,10 @@
         "message": "Add Username-only option for the site",
         "description": "Button text for adding Username-only option."
     },
+    "popupAllowIframeButton": {
+        "message": "Allow Cross-Origin iframes for the site",
+        "description": "Button text for allowing Cross-Origin iframes option."
+    },
     "popupErrorEncountered": {
         "message": "KeePassXC-Browser has encountered an error:",
         "description": "A text shown above error message in the popup."
@@ -447,6 +451,10 @@
         "message": "Only a single username field was detected. Add the URL to Site Preferences with Username-only option enabled?",
         "description": "Text shown when page can be added to Site Preferences with Username-only option enabled."
     },
+    "popupIframeDetected": {
+        "message": "A Cross-Origin iframe was detected. Add the URL to Site Preferences with Allow Cross-Origin iframes option enabled?",
+        "description": "Text shown when page can be added to Site Preferences with Allow Cross-Origin iframes option enabled."
+    },
     "rememberInfoText": {
         "message": "Username or password changed! Save it?",
         "description": "Message when username or password has changed."
@@ -1007,6 +1015,10 @@
         "message": "Improved Input Field Detection",
         "description": "Improved Input Field Detection column text."
     },
+    "optionsColumnAllowIframes": {
+        "message": "Allow Cross-Origin iframes",
+        "description": "Allow iframes column text."
+  },
     "optionsColumnDelete": {
         "message": "Delete",
         "description": "Site preferences list column title."
@@ -1127,6 +1139,10 @@
         "message": "Improved Input Field Detection allows more detailed dynamic input field detection. However, it might affect the page performance. Use with caution.",
         "description": "Improved Input Field Detection help text."
     },
+    "optionsSitePreferencesAllowIframesHelpText": {
+        "message": "Allowing Cross-Origin iframes will enable credential retrieval for iframes from another domain. Use at your own risk.",
+        "description": "Allow Cross-Origin iframes help text."
+    },
     "optionsSitePreferencesManualAddText": {
         "message": "Add URL manually",
         "description": "Label for adding site manually on Site preferences tab."
diff --git a/keepassxc-browser/background/event.js b/keepassxc-browser/background/event.js
index 583f8c4..ebb197b 100755
--- a/keepassxc-browser/background/event.js
+++ b/keepassxc-browser/background/event.js
@@ -26,18 +26,21 @@ kpxcEvent.showStatus = async function(tab, configured, internalPoll) {
 
     const errorMessage = page.tabs[tab.id]?.errorMessage ?? undefined;
     const usernameFieldDetected = page.tabs[tab.id]?.usernameFieldDetected ?? false;
+    const iframeDetected = page.tabs[tab.id]?.iframeDetected ?? false;
 
     return {
-        identifier: keyId,
+        associated: keepass.isAssociated(),
+
         configured: configured,
         databaseClosed: keepass.isDatabaseClosed,
-        keePassXCAvailable: keepass.isKeePassXCAvailable,
         encryptionKeyUnrecognized: keepass.isEncryptionKeyUnrecognized,
-        associated: keepass.isAssociated(),
         error: errorMessage,
-        usernameFieldDetected: usernameFieldDetected,
+        iframeDetected: iframeDetected,
+        identifier: keyId,
+        keePassXCAvailable: keepass.isKeePassXCAvailable,
         showGettingStartedGuideAlert: page.settings.showGettingStartedGuideAlert,
-        showTroubleshootingGuideAlert: page.settings.showTroubleshootingGuideAlert
+        showTroubleshootingGuideAlert: page.settings.showTroubleshootingGuideAlert,
+        usernameFieldDetected: usernameFieldDetected
     };
 };
 
@@ -177,6 +180,10 @@ kpxcEvent.onUsernameFieldDetected = async function(tab, detected) {
     page.tabs[tab.id].usernameFieldDetected = detected;
 };
 
+kpxcEvent.onIframeDetected = async function(tab, detected) {
+    page.tabs[tab.id].iframeDetected = detected;
+};
+
 kpxcEvent.passwordGetFilled = async function() {
     return page.passwordFilled;
 };
@@ -251,6 +258,7 @@ kpxcEvent.messageHandlers = {
     'get_totp': keepass.getTotp,
     'hide_getting_started_guide_alert': kpxcEvent.hideGettingStartedGuideAlert,
     'hide_troubleshooting_guide_alert': kpxcEvent.hideTroubleshootingGuideAlert,
+    'iframe_detected': kpxcEvent.onIframeDetected,
     'init_http_auth': kpxcEvent.initHttpAuth,
     'is_connected': kpxcEvent.getIsKeePassXCAvailable,
     'is_iframe_allowed': page.isIframeAllowed,
@@ -264,6 +272,7 @@ kpxcEvent.messageHandlers = {
     'page_get_manual_fill': page.getManualFill,
     'page_get_redirect_count': kpxcEvent.pageGetRedirectCount,
     'page_get_submitted': page.getSubmitted,
+    'page_set_allow_iframes': page.setAllowIframes,
     'page_set_autosubmit_performed': page.setAutoSubmitPerformed,
     'page_set_login_id': page.setLoginId,
     'page_set_manual_fill': page.setManualFill,
diff --git a/keepassxc-browser/background/page.js b/keepassxc-browser/background/page.js
index 5a0a49b..7035fb0 100755
--- a/keepassxc-browser/background/page.js
+++ b/keepassxc-browser/background/page.js
@@ -154,6 +154,7 @@ page.clearLogins = function(tabId) {
         return;
     }
 
+    page.tabs[tabId].allowIframes = false;
     page.tabs[tabId].credentials = [];
     page.tabs[tabId].loginList = [];
     page.currentRequest = {};
@@ -185,6 +186,7 @@ page.clearSubmittedCredentials = async function() {
 
 page.createTabEntry = function(tabId) {
     page.tabs[tabId] = {
+        allowIframes: false,
         credentials: [],
         errorMessage: null,
         loginList: [],
@@ -329,10 +331,24 @@ page.updatePopup = function(tab) {
     browserAction.showDefault(tab);
 };
 
+page.setAllowIframes = async function(tab, args = []) {
+    const [ allowIframes, site ] = args;
+
+    // Only set when main windows' URL is used
+    if (tab?.url === site) {
+        page.tabs[tab.id].allowIframes = allowIframes;
+    }
+};
+
 page.isIframeAllowed = async function(tab, args = []) {
     const [ url, hostname ] = args;
     const baseDomain = await page.getBaseDomainFromUrl(hostname, url);
 
+    // Allow if exception has been set from Site Preferences
+    if (page.tabs[tab.id]?.allowIframes) {
+        return true;
+    }
+
     // Allow iframe if the base domain is included in iframes' and tab's hostname
     const tabUrl = new URL(tab?.url);
     return hostname.endsWith(baseDomain) && tabUrl.hostname?.endsWith(baseDomain);
diff --git a/keepassxc-browser/content/keepassxc-browser.js b/keepassxc-browser/content/keepassxc-browser.js
index 9fd84d5..20a9b02 100755
--- a/keepassxc-browser/content/keepassxc-browser.js
+++ b/keepassxc-browser/content/keepassxc-browser.js
@@ -27,8 +27,8 @@ kpxc.singleInputEnabledForPage = false;
 kpxc.submitUrl = null;
 kpxc.url = null;
 
-// Add page to Site Preferences with Username-only detection enabled. Set from the popup
-kpxc.addToSitePreferences = async function() {
+// Add page to Site Preferences with a selected option enabled. Set from the popup.
+kpxc.addToSitePreferences = async function(optionName, addWildcard = false) {
     // Returns a predefined URL for certain sites
     let site = trimURL(window.top.location.href).toLowerCase();
 
@@ -37,24 +37,32 @@ kpxc.addToSitePreferences = async function() {
     for (const existingSite of kpxc.settings['sitePreferences']) {
         if (existingSite.url === site) {
             existingSite.ignore = IGNORE_NOTHING;
-            existingSite.usernameOnly = true;
+            existingSite[optionName] = true;
             siteExists = true;
         }
     }
 
     if (!siteExists) {
         // Add wildcard to the URL
-        site = site.slice(0, site.lastIndexOf('/') + 1) + '*';
+        if (addWildcard) {
+            site = site.slice(0, site.lastIndexOf('/') + 1) + '*';
+        }
 
         kpxc.settings['sitePreferences'].push({
             url: site,
             ignore: IGNORE_NOTHING,
-            usernameOnly: true
+            [optionName]: true
         });
     }
 
     await sendMessage('save_settings', kpxc.settings);
-    sendMessage('username_field_detected', false);
+
+    if (optionName === 'allowIframes') {
+        await sendMessage('page_set_allow_iframes', [ true, site ]);
+        await sendMessage('iframe_detected', false);
+    } else if (optionName === 'usernameOnly') {
+        await sendMessage('username_field_detected', false);
+    }
 };
 
 // Clears all from the content and background scripts, including autocomplete
@@ -706,6 +714,7 @@ kpxc.siteIgnored = async function(condition) {
             currentLocation = window.self.location.href.toLowerCase();
         }
 
+        // Refresh current settings for the site
         const currentSetting = condition || IGNORE_FULL;
         for (const site of kpxc.settings.sitePreferences) {
             if (siteMatch(site.url, currentLocation) || site.url === currentLocation) {
@@ -715,6 +724,7 @@ kpxc.siteIgnored = async function(condition) {
 
                 kpxc.singleInputEnabledForPage = site.usernameOnly;
                 kpxc.improvedFieldDetectionEnabledForPage = site.improvedFieldDetection;
+                await sendMessage('page_set_allow_iframes', [ site.allowIframes, currentLocation ]);
             }
         }
 
@@ -897,8 +907,10 @@ browser.runtime.onMessage.addListener(async function(req, sender) {
 
         if (req.action === 'activated_tab') {
             kpxc.triggerActivatedTab();
+        } else if (req.action === 'add_allow_iframes_option') {
+            kpxc.addToSitePreferences('allowIframes');
         } else if (req.action === 'add_username_only_option') {
-            kpxc.addToSitePreferences();
+            kpxc.addToSitePreferences('usernameOnly', true);
         } else if (req.action === 'check_database_hash' && 'hash' in req) {
             kpxc.detectDatabaseChange(req);
         } else if (req.action === 'choose_credential_fields') {
@@ -969,6 +981,7 @@ kpxc.reconnect = async function() {
 };
 
 const isIframeAllowed = async function() {
+    sendMessage('iframe_detected', false);
     try {
         // Check for Cross-domain security error when inspecting window.top.location.href
         const currentLocation = window.top.location.href;
@@ -980,8 +993,8 @@ const isIframeAllowed = async function() {
             return true;
         }
 
-        // TODO: Allow user to add a manual exception for iframes with this tab URL
         logDebug(`Error: Credential request ignored from another domain: ${window.self.location.host}`);
+        sendMessage('iframe_detected', true);
         return false;
     }
 };
diff --git a/keepassxc-browser/options/options.css b/keepassxc-browser/options/options.css
index 77f3bd2..da74ffe 100644
--- a/keepassxc-browser/options/options.css
+++ b/keepassxc-browser/options/options.css
@@ -128,6 +128,7 @@ table tbody tr.empty:not(:nth-last-child(2)) {
 
 #tab-site-preferences td:nth-of-type(3),
 #tab-site-preferences td:nth-of-type(4),
+#tab-site-preferences td:nth-of-type(5),
 table td:last-of-type {
     width: 1px;
 }
diff --git a/keepassxc-browser/options/options.html b/keepassxc-browser/options/options.html
index 10f4ede..25f546c 100644
--- a/keepassxc-browser/options/options.html
+++ b/keepassxc-browser/options/options.html
@@ -69,7 +69,7 @@
             </ul>
           </div>
           <footer class="px-3 mt-4 mb-1 text-uppercase position-absolute small text-muted">
-            © 2017-2023 - KeePassXC Team
+            © 2017-2024 - KeePassXC Team
           </footer>
         </nav>
 
@@ -686,6 +686,7 @@
                       <li><span data-i18n="optionsSitePreferencesTabHelpTextThird"></span></li>
                       <li><span data-i18n="optionsSitePreferencesTabHelpTextFourth"></span></li>
                       <li><span data-i18n="optionsSitePreferencesImprovedInputFieldDetectionHelpText"></span></li>
+                      <li><span data-i18n="optionsSitePreferencesAllowIframesHelpText"></span></li>
                     </ul>
                   </div>
                   <hr class="mt-0">
@@ -711,6 +712,7 @@
                           <th scope="col"><span data-i18n="optionsColumnIgnore"></span></th>
                           <th scope="col"><span data-i18n="optionsColumnUsernameOnly"></span></th>
                           <th scope="col"><span data-i18n="optionsColumnImprovedInputFieldDetection"></span></th>
+                          <th scope="col"><span data-i18n="optionsColumnAllowIframes"></span></th>
                           <th scope="col"><span data-i18n="optionsColumnDelete"></span></th>
                         </tr>
                       </thead>
@@ -730,6 +732,7 @@
                           </td>
                           <td><input class="form-check-input" type="checkbox" name="usernameOnly" value="false" data-i18n="[title]optionsColumnUsernameOnly"></td>
                           <td><input class="form-check-input" type="checkbox" name="improvedFieldDetection" value="false" data-i18n="[title]optionsColumnImprovedInputFieldDetection"></td>
+                          <td><input class="form-check-input" type="checkbox" name="allowIframes" value="false" data-i18n="[title]optionsColumnAllowIframes"></td>
                           <td class="text-nowrap">
                             <button class="btn btn-sm delete btn-danger btn">
                               <i class="fa fa-remove" aria-hidden="true"></i>
diff --git a/keepassxc-browser/options/options.js b/keepassxc-browser/options/options.js
index 0fdb3fa..1119136 100644
--- a/keepassxc-browser/options/options.js
+++ b/keepassxc-browser/options/options.js
@@ -395,8 +395,12 @@ options.initConnectedDatabases = function() {
         row.setAttribute('hash', hash);
         row.setAttribute('id', 'tr-cd-' + hash);
 
-        const lastUsed = (options.keyRing[hash].lastUsed) ? new Date(options.keyRing[hash].lastUsed).toLocaleString() : 'unknown';
-        const date = (options.keyRing[hash].created) ? new Date(options.keyRing[hash].created).toLocaleDateString() : 'unknown';
+        const lastUsed = options.keyRing[hash].lastUsed
+            ? new Date(options.keyRing[hash].lastUsed).toLocaleString()
+            : 'unknown';
+        const date = options.keyRing[hash].created
+            ? new Date(options.keyRing[hash].created).toLocaleDateString()
+            : 'unknown';
 
         row.children[0].textContent = options.keyRing[hash].id;
         row.children[1].textContent = options.getPartiallyHiddenKey(options.keyRing[hash].key);
@@ -513,6 +517,8 @@ options.initSitePreferences = function() {
                     site.usernameOnly = this.checked;
                 } else if (this.name === 'improvedFieldDetection') {
                     site.improvedFieldDetection = this.checked;
+                } else if (this.name === 'allowIframes') {
+                    site.allowIframes = this.checked;
                 }
             }
         }
@@ -533,7 +539,7 @@ options.initSitePreferences = function() {
         options.saveSettings();
     };
 
-    const addNewRow = function(rowClone, newIndex, url, ignore, usernameOnly, improvedFieldDetection) {
+    const addNewRow = function(rowClone, newIndex, url, ignore, usernameOnly, improvedFieldDetection, allowIframes) {
         const row = rowClone.cloneNode(true);
         row.setAttribute('url', url);
         row.setAttribute('id', 'tr-scf' + newIndex);
@@ -544,7 +550,9 @@ options.initSitePreferences = function() {
         row.children[2].children['usernameOnly'].addEventListener('change', checkboxClicked);
         row.children[3].children['improvedFieldDetection'].checked = improvedFieldDetection;
         row.children[3].children['improvedFieldDetection'].addEventListener('change', checkboxClicked);
-        row.children[4].addEventListener('click', removeButtonClicked);
+        row.children[4].children['allowIframes'].checked = allowIframes;
+        row.children[4].children['allowIframes'].addEventListener('change', checkboxClicked);
+        row.children[5].addEventListener('click', removeButtonClicked);
 
         $('#tab-site-preferences table tbody').append(row);
     };
@@ -604,10 +612,16 @@ options.initSitePreferences = function() {
         const rowClone = $('#tab-site-preferences table tr.clone').cloneNode(true);
         rowClone.classList.remove('clone', 'd-none');
 
-        addNewRow(rowClone, newIndex, value, IGNORE_NOTHING, false, false);
+        addNewRow(rowClone, newIndex, value, IGNORE_NOTHING, false, false, false);
         $('#tab-site-preferences table tbody tr.empty').hide();
 
-        options.settings['sitePreferences'].push({ url: value, ignore: IGNORE_NOTHING, usernameOnly: false, improvedFieldDetection: false });
+        options.settings['sitePreferences'].push({
+            url: value,
+            ignore: IGNORE_NOTHING,
+            usernameOnly: false,
+            improvedFieldDetection: false,
+            allowIframes: false,
+        });
         options.saveSettings();
         manualUrl.value = '';
     });
@@ -617,7 +631,15 @@ options.initSitePreferences = function() {
     let counter = 1;
     if (options.settings['sitePreferences']) {
         for (const site of options.settings['sitePreferences']) {
-            addNewRow(rowClone, counter, site.url, site.ignore, site.usernameOnly, site.improvedFieldDetection);
+            addNewRow(
+                rowClone,
+                counter,
+                site.url,
+                site.ignore,
+                site.usernameOnly,
+                site.improvedFieldDetection,
+                site.allowIframes,
+            );
             ++counter;
         }
     }
diff --git a/keepassxc-browser/popups/popup.html b/keepassxc-browser/popups/popup.html
index 45a01da..567fd1c 100644
--- a/keepassxc-browser/popups/popup.html
+++ b/keepassxc-browser/popups/popup.html
@@ -130,6 +130,17 @@
           </button>
         </div>
       </div>
+
+      <div id="iframe-detected" style="display: none">
+        <hr>
+        <p data-i18n="popupIframeDetected"></p>
+        <div class="right-align">
+          <button id="allow-iframe-button" class="btn btn-sm btn-primary">
+            <i class="fa fa-plus" aria-hidden="true"></i>
+            <span data-i18n="popupAllowIframeButton"></span>
+          </button>
+        </div>
+      </div>
     </div>
   </body>
 </html>
diff --git a/keepassxc-browser/popups/popup.js b/keepassxc-browser/popups/popup.js
index 3523cf3..2823284 100644
--- a/keepassxc-browser/popups/popup.js
+++ b/keepassxc-browser/popups/popup.js
@@ -57,6 +57,10 @@ function statusResponse(r) {
             $('#username-field-detected').show();
         }
 
+        if (r.iframeDetected) {
+            $('#iframe-detected').show();
+        }
+
         reloadCount = 0;
     }
 }
@@ -137,6 +141,12 @@ const sendMessageToTab = async function(message) {
         $('#username-field-detected').hide();
     });
 
+    $('#allow-iframe-button').addEventListener('click', async () => {
+        await sendMessageToTab('add_allow_iframes_option');
+        await sendMessageToTab('redetect_fields');
+        $('#iframe-detected').hide();
+    });
+
     $('#getting-started-alert-close-button').addEventListener('click', async () => {
         await browser.runtime.sendMessage({
             action: 'hide_getting_started_guide_alert'