The Simple Download Counter plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'sdc_menu' shortcode in all versions up to, and including, 2.3. This is due to insufficient input sanitization and output escaping on user-supplied shortcode attributes, specifically the 'text' and 'cat' attributes. The 'text' attribute is output directly into HTML content on line 159 without any escaping (e.g., esc_html()). The 'cat' attribute is used unescaped in HTML class attributes on lines 135 and 157 without esc_attr(). This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

The Bread & Butter plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'breadbutter-customevent-button' shortcode in all versions up to, and including, 8.2.0.25. This is due to insufficient input sanitization and output escaping on the 'event' shortcode attribute. The customEventShortCodeButton() function takes the 'event' attribute value and directly interpolates it into a JavaScript string within an onclick HTML attribute without applying esc_attr() or esc_js(). Notably, the sister function customEventShortCode() properly uses esc_js() for the same attribute, but this was omitted in the button variant. This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses the page and clicks the injected button.

The LightPress Lightbox plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the `group` attribute in the `[gallery]` shortcode in all versions up to, and including, 2.3.4. This is due to the plugin modifying gallery shortcode output to include the `group` attribute value without proper escaping. This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

The CI HUB Connector plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'id' attribute of the `cihub_metadata` shortcode in all versions up to, and including, 1.2.106 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

The DSGVO snippet for Leaflet Map and its Extensions plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the `leafext-cookie-time` and `leafext-delete-cookie` shortcodes in all versions up to, and including, 3.1. This is due to insufficient input sanitization and output escaping on user supplied attributes (`unset`, `before`, `after`). This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

The Ultimate Blocks – WordPress Blocks Plugin plugin for WordPress is vulnerable to Stored Cross-Site Scripting via multiple widgets in all versions up to, and including, 3.3.3 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

The aBlocks – WordPress Gutenberg Blocks plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the "Table Of Content" Block, specifically in the "markerView" attribute, in all versions up to, and including, 1.6.1 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

The WordPress Button Plugin MaxButtons plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's shortcode(s) in all versions up to, and including 9.7.6 due to insufficient input sanitization and output escaping on user supplied attributes. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. NOTE: This vulnerability was partially fixed in version 9.7.6.

The Switch CTA Box plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'wppw_cta_box' shortcode in all versions up to, and including, 1.1. This is due to insufficient input sanitization and output escaping on user-supplied post meta values including 'cta_box_button_link', 'cta_box_button_id', 'cta_box_button_text', and 'cta_box_description'. The shortcode reads post meta from a user-specified post ID and echoes these values directly into HTML output without any escaping functions (no esc_attr(), esc_url(), or esc_html()). This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

The Shortcodes and extra features for Phlox theme plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the custom JS parameter in all versions up to, and including, 2.15.7 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with contributor access or higher, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

The Twittee Text Tweet plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'id' shortcode attribute in all versions up to and including 1.0.8. This is due to insufficient input sanitization and output escaping on user-supplied shortcode attributes. The ttt_twittee_tweeter() function uses extract() to pull shortcode attributes into local variables and then directly concatenates them into HTML output without any escaping. Specifically, the $id parameter is inserted into an HTML id attribute context without esc_attr(), allowing an attacker to break out of the attribute and inject arbitrary HTML event handlers. Additionally, the $tweet, $content, $balloon, and $theme attributes are similarly injected into inline JavaScript without escaping (lines 87, 93, 101, 117). This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

The Info Cards – Add Text and Media in Card Layouts plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'btnUrl' parameter within the Info Cards block in all versions up to, and including, 2.0.7. This is due to insufficient input validation on URL schemes, specifically the lack of javascript: protocol filtering. The block's render.php passes all attributes as JSON to the frontend via a data-attributes HTML attribute using esc_attr(wp_json_encode()), which prevents HTML attribute injection but does not validate URL protocols within the JSON data. The client-side view.js then renders the btnUrl value directly as an href attribute on anchor elements without any protocol sanitization. This makes it possible for authenticated attackers, with Contributor-level access and above, to inject javascript: URLs that execute arbitrary web scripts when a user clicks the rendered button link.

The Essential Blocks – Page Builder Gutenberg Blocks, Patterns & Templates plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the Table of Contents block in all versions up to, and including, 4.4.6 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

Marko is a declarative, HTML-based language for building web apps. Prior to marko version 5.38.36 and prior to @marko/runtime-tags 6.0.164, when dynamic text is interpolated into a <script> or <style> tag the Marko runtime failed to prevent tag breakout when the closing tag used non-lowercase casing. An attacker able to place input inside a <script> or <style> block could break out of the tag with </SCRIPT>, </Style>, etc. and inject arbitrary HTML/JavaScript, resulting in cross-site scripting. This issue has been patched in marko version 5.38.36 and @marko/runtime-tags 6.0.164.

The POWR plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's 'powr-powr-pack' shortcode in all versions up to, and including, 2.1.0 due to insufficient input sanitization and output escaping on user supplied attributes. This makes it possible for authenticated attackers with contributor-level and above permissions to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

The WPMK Block plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'class' shortcode attribute in all versions up to and including 1.0.1. This is due to insufficient input sanitization and output escaping on user-supplied shortcode attributes. Specifically, in the wpmk_block_shortcode() function, the 'class' attribute is extracted from user-controllable shortcode attributes and directly concatenated into an HTML div element's class attribute without any escaping (e.g., esc_attr()). This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

The PrivateContent Free plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'align' shortcode attribute in the [pc-login-form] shortcode in all versions up to, and including, 1.2.0. This is due to insufficient input sanitization and output escaping on the 'align' attribute. Specifically, the attribute value flows from the shortcode through pc_login_form() to pc_static::form_align(), where it is directly concatenated into an HTML class attribute without esc_attr() or any escaping. This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

The WM JqMath plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'style' shortcode attribute of the [jqmath] shortcode in all versions up to and including 1.3. This is due to insufficient input sanitization and output escaping on user-supplied shortcode attributes. The generate_jqMathFormula() function directly concatenates the 'style' attribute value into an HTML style attribute without applying esc_attr() or any other escaping. This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

The Simple Draft List plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'display_name' post meta (Custom Field) in all versions up to and including 2.6.2. This is due to insufficient input sanitization and output escaping on the author display name when no author URL is present. The plugin accesses `$draft_data->display_name` which, because `display_name` is not a native WP_Post property, triggers WP_Post::__get() and resolves to `get_post_meta($post_id, 'display_name', true)`. When the `user_url` meta field is empty, the `$author` value is assigned to `$author_link` on line 383 without any escaping (unlike line 378 which uses `esc_html()` for the `{{author}}` tag, and line 381 which uses `esc_html()` when a URL is present). This unescaped value is then inserted into the shortcode output via `str_replace()`. This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses a page containing the `[drafts]` shortcode with the `{{author+link}}` template tag.

The WP Games Embed plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the [game] shortcode in all versions up to and including 0.1beta. This is due to insufficient input sanitization and output escaping on user-supplied shortcode attributes such as 'width', 'height', 'src', 'title', 'description', 'game_url', 'main', and 'thumb', which are all directly concatenated into HTML output without any escaping. This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

The WordPress PayPal Donation plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'donate' shortcode in all versions up to, and including, 1.01. This is due to insufficient input sanitization and output escaping on user-supplied shortcode attributes such as 'amount', 'email', 'title', 'return_url', 'cancel_url', 'ccode', and 'image'. The wordpress_paypal_donation_create() function uses extract(shortcode_atts(...)) to process shortcode attributes and then directly interpolates these values into HTML output within single-quoted attribute values without any escaping. This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

The WP Random Button plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'cat', 'nocat', and 'text' shortcode attributes of the 'wp_random_button' shortcode in all versions up to, and including, 1.0. This is due to insufficient input sanitization and output escaping on user-supplied shortcode attributes. Specifically, the random_button_html() function directly concatenates the 'cat' and 'nocat' parameters into HTML data-attributes without esc_attr(), and the 'text' parameter into HTML content without esc_html(). This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

The VK Filter Search plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's 'vk_filter_search' shortcode in all versions up to, and including, 2.3.1 due to insufficient input sanitization and output escaping on user supplied attributes. This makes it possible for authenticated attackers with contributor-level and above permissions to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

The Ecover Builder For Dummies plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'id' parameter of the 'ecover' shortcode in all versions up to and including 1.0. This is due to insufficient input sanitization and output escaping on the user-supplied 'id' shortcode attribute. This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

The Social Feed plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's 'socialfeed' shortcode in all versions up to, and including, 1.5.4.6 due to insufficient input sanitization and output escaping on user supplied attributes. This makes it possible for authenticated attackers with author-level and above permissions to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

The pdfl.io plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'pdflio' shortcode in all versions up to, and including, 1.0.5. This is due to insufficient input sanitization and output escaping on the 'text' shortcode attribute. The output_shortcode() function directly concatenates the user-supplied $text variable into HTML output without applying esc_html() or any other escaping function. This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

The Easy Social Photos Gallery plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'wrapper_class' shortcode attribute of the 'my-instagram-feed' shortcode in all versions up to, and including, 3.1.2. This is due to insufficient input sanitization and output escaping on user supplied attributes. Specifically, the plugin uses sanitize_text_field() instead of esc_attr() when outputting the 'wrapper_class' attribute inside a double-quoted HTML class attribute. Since sanitize_text_field() does not encode double quotes, an attacker can break out of the class attribute and inject arbitrary HTML event handlers. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

The Automatically Hierarchic Categories in Menu plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's 'autocategorymenu' shortcode in all versions up to, and including, 2.0.7 due to insufficient input sanitization and output escaping on user supplied attributes. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

The WP-Asambleas plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's 'polls_popup' shortcode in all versions up to, and including, 2.85.0 due to insufficient input sanitization and output escaping on user supplied attributes. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

The Orbit Fox by ThemeIsle plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the ‘title_tag’ parameter in all versions up to, and including, 2.10.43 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

The Power Charts Lite plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'id' parameter of the [pc] shortcode in all versions up to, and including, 0.1.0. This is due to insufficient input sanitization and output escaping on the 'id' shortcode attribute. Specifically, in the pc_shortcode() function, the 'id' attribute is extracted from user-supplied shortcode attributes and directly concatenated into an HTML div element's class attribute without any escaping or sanitization at line 62. The resulting HTML is then passed through html_entity_decode() before being returned, further undermining any potential safety. This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

The Coachific Shortcode plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'userhash' shortcode attribute in all versions up to and including 1.0. This is due to insufficient input sanitization and output escaping. The plugin uses sanitize_text_field() on the 'userhash' parameter, which strips HTML tags but does not escape characters significant in a JavaScript string context (such as double quotes, semicolons, and parentheses). The sanitized value is then directly interpolated into a JavaScript string within a <script> tag on line 29 without any JavaScript-specific escaping (e.g., wp_json_encode() or esc_js()). This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

The HurryTimer – An Scarcity and Urgency Countdown Timer for WordPress & WooCommerce plugin for WordPress is vulnerable to Stored Cross-Site Scripting in all versions up to, and including, 2.11.2 due to insufficient input sanitization and output escaping of a campaign name. This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

The ER Swiffy Insert plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the [swiffy] shortcode in all versions up to and including 1.0.0. This is due to insufficient input sanitization and output escaping on user-supplied shortcode attributes ('n', 'w', 'h'). These attributes are extracted using extract() and directly interpolated into the HTML output without any escaping such as esc_attr(). This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

The Calculated Fields Form plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the form settings in all versions up to, and including, 5.4.5.0. This is due to insufficient capability checks on the form settings save handler and insufficient input sanitization of the `fcontent` field in `fhtml` field types. This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

The Show Posts list – Easy designs, filters and more plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'post_type' shortcode attribute in the 'swiftpost-list' shortcode in all versions up to, and including, 1.1.0 due to insufficient input sanitization and output escaping on user-supplied attributes. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

The fyyd podcast shortcodes plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'fyyd-podcast', 'fyyd-episode', and 'fyyd' shortcodes in all versions up to, and including, 0.3.1. This is due to insufficient input sanitization and output escaping on user-supplied shortcode attributes such as 'color', 'podcast_id', and 'podcast_slug'. These attributes are directly concatenated into inline JavaScript within single-quoted string arguments without any escaping or sanitization, allowing an attacker to break out of the JavaScript string context. This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

The WP Circliful plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'id' shortcode attribute of the [circliful] shortcode and via multiple shortcode attributes of the [circliful_direct] shortcode in all versions up to and including 1.2. This is due to insufficient input sanitization and output escaping on user-supplied shortcode attributes. Specifically, in the circliful_shortcode() function, the 'id' attribute value is concatenated directly into an HTML id attribute (line 285) without any escaping, allowing an attacker to break out of the double-quoted attribute and inject arbitrary HTML event handlers. Similarly, the circliful_direct_shortcode() function (line 257) outputs all shortcode attributes directly into HTML data-* attributes without escaping. This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

The Card Elements for Elementor plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's Profile Card widget in all versions up to, and including, 1.2.6 due to insufficient input sanitization and output escaping on user supplied attributes. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

The Rank Math SEO – AI SEO Tools to Dominate SEO Rankings plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's Rank Math API in all versions up to, and including, 1.0.235 due to insufficient input sanitization and output escaping on user supplied attributes. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

The Sheets2Table plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'titles' shortcode attribute in the [sheets2table-render-table] shortcode in all versions up to and including 0.4.1. This is due to insufficient input sanitization and output escaping. Specifically, the 'titles' attribute value from the shortcode is passed through S2T_Functions::trim_array_values() (which only trims whitespace) and then echoed directly into HTML via `echo $header` inside a <th> tag in the display_table_header() function without any escaping such as esc_html(). This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

An XSS issue was discovered in the Link iframe formatter module before 1.x-1.1.1 for Backdrop CMS. It doesn't sufficiently sanitize input before displaying results to the screen. This vulnerability is mitigated by the fact that an attacker must have the ability to create content containing an iFrame field.

The WP Shortcodes Plugin — Shortcodes Ultimate plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's su_meta shortcode combined with post meta data in all versions up to, and including, 5.13.3 due to insufficient input sanitization and output escaping on user supplied meta values. This makes it possible for authenticated attackers with contributor-level and above permissions to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

The Booster for WooCommerce plugin for WordPress is vulnerable to Stored Cross-Site Scripting via 'wcj_image' shortcode in versions up to, and including, 7.1.2 due to insufficient input sanitization and output escaping on user supplied attributes. This makes it possible for authenticated attackers with contributor-level and above permissions to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

XenForo before 2.3.10 and before 2.2.19 is vulnerable to stored cross-site scripting (XSS) in structured text mentions, primarily affecting legacy profile post content. An attacker can inject malicious scripts through crafted mentions that are stored and executed when other users view the content.

The Sherk Custom Post Type Displays plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'title' shortcode attribute in all versions up to, and including, 1.2.1. This is due to insufficient input sanitization and output escaping on the 'title' attribute of the 'sherkcptdisplays' shortcode. Specifically, in the sherkcptdisplays_func() function in includes/SherkCPTDisplaysShortcode.php, the 'title' attribute value is extracted from shortcode_atts() on line 19 and directly concatenated into an HTML <h2> tag on line 31 without any escaping. This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

The Newsletter2Go plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the ‘style’ parameter in all versions up to, and including, 4.0.14 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with subscriber access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

The WP Shortcodes Plugin — Shortcodes Ultimate plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's 'su_box' shortcode in all versions up to, and including, 7.4.9 due to insufficient input sanitization and output escaping on user supplied attributes. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

The Kona Gallery Block plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the "Kona: Instagram for Gutenberg" Block, specifically in the "align" attribute, in all versions up to, and including, 1.7 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

The All Bootstrap Blocks plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the "Accordion" widget in all versions up to, and including, 1.3.26 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.