Weakness (CWE)
CWE-79: Cross-site Scripting
The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.
How to prevent it (8 mitigations)
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Architecture and Design
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid [REF-1482].
Examples of libraries and frameworks that make it easier to generate properly encoded output include Microsoft's Anti-XSS library, the OWASP ESAPI Encoding module, and Apache Wicket.
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Implementation, Architecture and Design
Understand the context in which your data will be used and the encoding that will be expected. This is especially important when transmitting data between different components, or when generating outputs that can contain multiple encodings at the same time, such as web pages or multi-part mail messages. Study all expected communication protocols and data representations to determine the required encoding strategies.
For any data that will be output to another web page, especially any data that was received from external inputs, use the appropriate encoding on all non-alphanumeric characters.
Parts of the same output document may require different encodings, which will vary depending on whether the output is in the:
- HTML body
- Element attributes (such as src="XYZ")
- URIs
- JavaScript sections
- Cascading Style Sheets and style property
etc. Note that HTML Entity Encoding is only appropriate for the HTML body.
Consult the XSS Prevention Cheat Sheet [REF-724] for more details on the types of encoding and escaping that are needed.
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Architecture and Design, Implementation
Understand all the potential areas where untrusted inputs can enter your software: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any external systems that provide data to the application. Remember that such inputs may be obtained indirectly through API calls.
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Architecture and Design
For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
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Architecture and Design
If available, use structured mechanisms that automatically enforce the separation between data and code. These mechanisms may be able to provide the relevant quoting, encoding, and validation automatically, instead of relying on the developer to provide this capability at every point where output is generated.
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Implementation
Use and specify an output encoding that can be handled by the downstream component that is reading the output. Common encodings include ISO-8859-1, UTF-7, and UTF-8. When an encoding is not specified, a downstream component may choose a different encoding, either by assuming a default encoding or automatically inferring which encoding is being used, which can be erroneous. When the encodings are inconsistent, the downstream component might treat some character or byte sequences as special, even if they are not special in the original encoding. Attackers might then be able to exploit this discrepancy and conduct injection attacks; they even might be able to bypass protection mechanisms that assume the original encoding is also being used by the downstream component.
The problem of inconsistent output encodings often arises in web pages. If an encoding is not specified in an HTTP header, web browsers often guess about which encoding is being used. This can open up the browser to subtle XSS attacks.
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Implementation
With Struts, write all data from form beans with the bean's filter attribute set to true.
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Implementation
To help mitigate XSS attacks against the user's session cookie, set the session cookie to be HttpOnly. In browsers that support the HttpOnly feature (such as more recent versions of Internet Explorer and Firefox), this attribute can prevent the user's session cookie from being accessible to malicious client-side scripts that use document.cookie. This is not a complete solution, since HttpOnly is not supported by all browsers. More importantly, XmlHttpRequest and other powerful browser technologies provide read access to HTTP headers, including the Set-Cookie header in which the HttpOnly flag is set.
Source: MITRE CWE-79
591 results · Clear filters · Feed
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Critical 9.6
Webmin: Reflected XSS in the Configuration module
Webmin is a web-based system administration tool for Unix-like servers. Prior to version 2.650, Webmin users who click on a malicious link to their server are vulnerable to this XSS vulnerability that could be used to execute attacker-controlled commands. Thi…
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Critical 9.6
Unauthenticated update of public UI settings leading to stored cross-site scripting in Rancher
An unauthenticated update of public UI settings could be used by remote attackers to execute a stored cross-site scripting attack in the Rancher UI, in SUSE Rancher 2.15 before 2.15.2, 2.14 before 2.14.6, 2.13 before 2.13.10, 2.12 before 2.12.14 and 2.11 befo…
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Critical 9.3
Zimbra Collaboration Suite Classic Web Client Stored Cross-Site Scripting via Crafted Calendar COUNTER Message From Address
An unauthenticated calendar sender can place active markup in a COUNTER message's RFC From address. Selecting the message in Zimbra Classic triggers stored XSS, allowing the attacker to access mailbox data and act as the victim.
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Critical 9.3
Zimbra Collaboration Suite Modern Web Client Stored Cross-Site Scripting via Forged Share Invitation
An unauthenticated sender can forge a share notification that triggers stored XSS when a signed-in Zimbra Modern recipient clicks Accept Share, allowing the attacker to access mailbox data and act as the victim.
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Critical 9.3
Zimbra Collaboration Suite Classic Web Client Stored Cross-Site Scripting via Forged Share Invitation
An unauthenticated sender can forge a share notification that triggers stored XSS when a signed-in Zimbra Classic recipient clicks Accept Share, allowing the attacker to access mailbox data and act as the victim.
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Critical 9.3
IBM Financial Transaction Manager (FTM) is Impacted by Multiple Vulnerabilities
IBM Financial Transaction Manager (FTM) for RedHat OpenShift is vulnerable to stored cross-site scripting (CWE-79) in the FTM UI NetworkAcknowledgement React component (NetworkAcknowledgement.jsx:42). A malicious actor can inject script into stored network ac…
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Critical 10.0
SunEditor: Critical XSS vulnerability - sanitizer bypass
SunEditor is a lightweight and powerful WYSIWYG editor in vanilla JavaScript with no dependencies. Prior to 2.47.11, the sanitizer in src/lib/core.js does not consistently reject namespaced or custom HTML elements, allowing event-handler attributes to remain …
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Critical 9.3
Adobe Connect | Cross-site Scripting (Stored XSS) (CWE-79)
Adobe Connect is affected by a stored Cross-Site Scripting (XSS) vulnerability that could be abused by an attacker to inject malicious scripts into vulnerable form fields. Malicious JavaScript may be executed in a victim's browser when they browse to the page…
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Critical 9.3
Adobe Connect | Cross-site Scripting (Reflected XSS) (CWE-79)
Adobe Connect is affected by a reflected Cross-Site Scripting (XSS) vulnerability. An attacker could exploit this vulnerability to inject malicious scripts into a web page, potentially gaining elevated access or control over the victim's account or session. E…
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Critical 9.3
Adobe Connect | Cross-site Scripting (Stored XSS) (CWE-79)
Adobe Connect is affected by a stored Cross-Site Scripting (XSS) vulnerability that could be abused by an attacker to inject malicious scripts into vulnerable form fields. Malicious JavaScript may be executed in a victim's browser when they browse to the page…
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Critical 9.3
Adobe Connect | Cross-site Scripting (Stored XSS) (CWE-79)
Adobe Connect is affected by a stored Cross-Site Scripting (XSS) vulnerability that could be abused by an attacker to inject malicious scripts into vulnerable form fields. Malicious JavaScript may be executed in a victim's browser when they browse to the page…
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Critical 9.3
Warpgate: Reflected XSS in SSO return endpoint via attacker-controlled next parameter
Warpgate is an open source SSH, HTTPS and MySQL bastion host for Linux. Prior to 0.25.5, the /@warpgate/api/sso/providers/:name/start endpoint stores an attacker-controlled next parameter that the POST /@warpgate/api/sso/return handler inserts without HTML es…
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Critical 9.0
IBM Guardium Data Protection is affected by multiple vulnerabilities.
IBM Guardium Data Protection 12.2 could allow a remote authenticated attacker to execute arbitrary code due to improper neutralization of input during web page generation.
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Critical 9.6
IBM Guardium Data Protection is affected by multiple vulnerabilities.
IBM Guardium Data Protection 12.2 could allow a remote authenticated attacker to execute arbitrary code due to improper neutralization of input during web page generation.
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Critical 9.0
Chamilo LMS: Student-to-admin stored XSS in private messages via v-html
Chamilo LMS is an open-source learning management system. From 2.0.0 through at least 2.1.0, Chamilo LMS stores private Message.content without server-side sanitization and renders it as HTML in assets/vue/views/message/MessageShow.vue and public/main/templat…
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Critical 9.3
Reflected Cross-Site Scripting
An attacker can craft a malicious link that, if used by a legitimate user, may cause the user's browser to run JavaScript supplied by the attacker.
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Critical 9.3
AVideo AD_Server Stored XSS via log.php label parameter
AVideo through commit c3edcc274c389816d434acadac07ee78eaf330c1 contains a stored cross-site scripting vulnerability in the AD_Server plugin's log.php endpoint that fails to escape the label parameter before storage. An unauthenticated attacker can inject mali…
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Critical 9.6
NationalSecurityAgency/skills-service has Stored XSS via User Registration Enabling Admin Account Takeover
SkillTree is a micro-learning gamification platform. Prior to version 4.4.2, two independent code flaws combine into a single exploitable attack chain, with three distinct exploitation paths of escalating impact. `StringHighlighter.js` builds an HTML string b…
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Critical 9.0
Stored Cross-Site Scripting (XSS) in Auth0 AD/LDAP Connector
The Auth0 AD/LDAP Connector is vulnerable to stored Cross-Site Scripting (XSS) issues due to improper HTML encoding of data in search results and updater log content displayed in the admin panel. An authenticated user with privileges to modify directory attri…
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Critical 9.3
Adobe Commerce | Cross-site Scripting (Stored XSS) (CWE-79)
Adobe Commerce is affected by a stored Cross-Site Scripting (XSS) vulnerability that could be abused by an attacker to inject malicious scripts into vulnerable form fields. Malicious JavaScript may be executed in a victim's browser when they browse to the pag…
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Critical 9.3
Adobe Commerce | Cross-site Scripting (Stored XSS) (CWE-79)
Adobe Commerce is affected by a stored Cross-Site Scripting (XSS) vulnerability that could be abused by an attacker to inject malicious scripts into vulnerable form fields. Malicious JavaScript may be executed in a victim's browser when they browse to the pag…
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Critical 9.3
Microsoft Exchange Server Spoofing Vulnerability
Improper neutralization of input during web page generation ('cross-site scripting') in Microsoft Exchange Server allows an unauthorized attacker to perform spoofing over a network.
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Critical 9.3
UC Browser for Android (package com.UCMobile.intl, version 13.7.8.1314) contains a Universal Cross-Site Scripting vulne…
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Critical 10.0
MapLibre GL JS: XSS Sanitizer Bypass in DOM.sanitize() via Live NamedNodeMap Removal Skip
MapLibre GL JS is an interactive vector tile map library for web browsers. Prior to 6.4.1, DOM.sanitize() in src/util/dom.ts iterates elem.attributes as a live NamedNodeMap while removeAttributes() removes attributes from the same collection, shifting indexes…
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Critical 9.2
Multiple vulnerabilities in Ocsreports for OCS Inventory NG
A stored Cross-Site Scripting (XSS) vulnerability in the notification template functionality of the endpoint /ocsreports/?function=notification. A user with administrator privileges can input malicious HTML content which is subsequently stored and displayed w…
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Critical 9.0
SiYuan before v3.8.2 Stored XSS via incomplete asset blocklist
SiYuan before v3.8.2 contains a stored cross-site scripting vulnerability in asset serving due to an incomplete extension blocklist that misses script-capable file types. Attackers can upload files with extensions like .xht, .ehtml, .xsl, .xbl, or .rdf that r…
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Critical 9.0
Authenticated Stored Cross-Site Scripting Vulnerability (XSS) in HPE Networking Fabric Composer Web-Based Management Interface
A vulnerability in the web-based management interface of HPE Networking Fabric Composer could allow an authenticated low privilege operator user to conduct a stored cross-site scripting (XSS) attack against an administrative user of the interface. A successfu…
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Critical 9.0
An improper neutralization of input during web page generation ('Cross-site Scripting') vulnerability in extract domain…
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Critical 9.2CVE-2026-82090 Public exploit
Pocket through 8.33.0.0 allows XSS because "Save to Pocket" injects external HTML into the DOM. JavaScript code can al…
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Critical 9.3
Trilium: Note Import to RCE via Book Note
Trilium is an open-source hierarchical note-taking application. In versions up to and including 0.103.0, the default-on "Safe import" filter sanitizes HTML only for text notes and excludes the book note type, whose content is stored without sanitization and l…
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Critical 9.3
Trilium: Note Import to RCE via Mind Elixir dangerouslySetInnerHtml
Trilium is an open-source hierarchical note-taking application. In versions up to and including 0.103.0, the default-on "Safe import" filter sanitizes HTML only for text notes and excludes the mindMap note type, whose JSON content is stored without sanitizati…
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Critical 9.3
Trilium: Malicious import with GeoMap marker title XSS leads to RCE on the desktop client
Trilium is an open-source hierarchical note-taking application. In versions up to and including 0.103.0, the default-on "Safe import" filter does not sanitize note titles, and the GeoMap note view interpolates a marker note's title into raw HTML that is rende…
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Critical 9.8
justhtml before 1.16.0 Multiple Security Issues via Sanitization
justhtml before 1.16.0 contains multiple HTML sanitization bypass issues that can allow active/dangerous content (e.g., script or style) to survive sanitization, potentially leading to cross-site scripting. The issues primarily affect advanced usage rather th…
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Critical 9.8
justhtml before 1.12.0 Sanitizer Bypass via Markdown
justhtml versions <= 1.11.0 (fixed in 1.12.0) do not sufficiently escape HTML-significant characters (angle brackets) in text nodes when converting a parsed document to Markdown via to_markdown(). While a small set of Markdown metacharacters are escaped, char…
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Critical 9.8
justhtml before 1.15.0 Multiple Security Issues
justhtml before 1.15.0 contains multiple security issues in URL sanitization helpers (clean_url_value/clean_url_in_js_string), HTML serialization, Markdown passthrough (html_passthrough=True), and several custom sanitization-policy edge cases. Depending on co…
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Critical 9.6
Etherpad: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in etherpad-lite
Etherpad is a real-time collaborative editor. Prior to 3.3.1, result.appendSpan in src/static/js/domline.ts interpolates the start attribute of a numbered list directly into an unquoted ol start attribute before assigning the generated markup to node.innerHTM…
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Critical 9.3
SpiderFoot Stored Cross-Site Scripting via Correlation Titles
SpiderFoot fails to HTML-escape correlation titles built from external scan data sources including server banners and metadata. Attackers can inject malicious HTML elements with event handlers into correlation results that execute scripts in the operator's br…
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Critical 9.3
Discourse: Cache poisoning/XSS via color scheme cookies
Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, an unauthenticated attacker could send a single request with a crafted color_scheme_id (or dark_scheme_id) cookie to inject arbitrary HTML into a Discourse p…
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Critical 9.0
SiYuan before v3.7.4 Stored XSS via assets endpoint
SiYuan before v3.7.4 fails to set Content-Disposition and X-Content-Type-Options headers when serving arbitrary file assets, allowing stored cross-site scripting attacks. Authenticated attackers can upload HTML files as assets and execute scripts with full ke…
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Critical 9.0
SiYuan before v3.7.4 Cross-Site Scripting via unicode2Emoji
SiYuan versions before v3.7.4 contain a cross-site scripting vulnerability in the unicode2Emoji function that fails to sanitize codepoint branch output. Attackers can craft document icons with hex-encoded markup that executes in the renderer with Node integra…