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
6,268 results · Clear filters · Feed
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High 7.2
WP-Lister Lite for eBay <= 3.8.9 - Unauthenticated Stored Cross-Site Scripting via AJAX Cron Handler Request
The WP-Lister Lite for eBay plugin for WordPress is vulnerable to Stored Cross-Site Scripting via AJAX Cron Handler Request Parameter in all versions up to, and including, 3.8.9 due to insufficient input sanitization and output escaping. This makes it possibl…
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High 7.3
Concrete CMS 9.0 to 9.5.2 is vulnerable to Stored XSS via group folder name on the Members > Groups dashboard
Concrete CMS 9.0.0 to 9.5.2 stored group folder names without sanitization and printed them unescaped on the Members > Groups dashboard page, resulting in stored cross-site scripting. The add and edit group-folder handlers stored the submitted folder name wit…
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High 7.5
Concrete CMS 9.0 to 9.5.2 is vulnerable to Stored XSS in the Top Navigation Bar Block via Dropdown Child Page Names
In Concrete CMS 9.0 to 9.5.2, the Top Navigation Bar block did not HTML-escape dropdown child page names before writing them into the page, so a user who could create or rename pages could store a script through a child page name and have it run in the browse…
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High 7.5
Concrete CMS below version 9.5.3 is vulnerable to Stored XSS via country-less Address attribute in Express association views
In Concrete CMS below version 9.5.3, the Address attribute's country-less text formatter skipped HTML-escaping, enabling stored XSS in Express association views. A user able to submit an Address attribute could execute script in the session of any dashboard u…
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High 7.7
Concrete CMS below version 9.5.3 is vulnerable to Stored XSS via Express form Text control save_control
In Concrete CMS below CMS 9.5.3, the save_control action in the Express entities forms dashboard controller did not validate the anti-CSRF token. By causing an authenticated administrator to submit a forged cross-site request, a remote attacker without creden…
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High 8.4
Concrete CMS below version 9.5.3 is vulnerable to Stored XSS in Concrete CMS Form Submissions Report via Unescaped Question Label
Concrete CMS before 9.5.3 does not apply HTML entity encoding to user-defined Form block question labels when rendering them as column headers in the Dashboard Form Submissions report (concrete/single_pages/dashboard/reports/forms/legacy.php). a rogue editor …
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High 8.6
EmbedVideo Extension : Stored XSS via unsanitized class passed to template
The EmbedVideo Extension is a MediaWiki extension which adds a parser function called #ev and various parser tags for embedding video clips from various video sharing services. Prior to 4.1.0, EmbedHtmlFormatter::toHtml in includes/EmbedService/EmbedHtmlForma…
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High 7.5
EmbedVideo Extension: Stored XSS via unsanitized service name in exception text
The EmbedVideo Extension is a MediaWiki extension which adds a parser function called #ev and various parser tags for embedding video clips from various video sharing services. Prior to 4.1.0, EmbedServiceFactory::newFromName in includes/EmbedService/EmbedSer…
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High 7.5
EmbedVideo Extension: Stored XSS via malformed src url with $wgEmbedVideoRequireConsent enabled
The EmbedVideo Extension is a MediaWiki extension which adds a parser function called #ev and various parser tags for embedding video clips from various video sharing services. Prior to 4.1.0, with the default $wgEmbedVideoRequireConsent configuration enabled…
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High 7.2
MotoPress Hotel Booking <= 6.2.4 - Unauthenticated Stored Cross-Site Scripting via Stripe Webhook Event Object 'id'
The MotoPress Hotel Booking plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the Stripe Webhook event object 'id' in all versions up to, and including, 6.2.4 due to insufficient input sanitization and output escaping. This makes it possib…
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High 8.3
OpenAM: Pre-auth Reflected XSS in OAuth2 / OIDC response_mode=form_post via state parameter (FormPostResponse.ftl)
Open Access Management (OpenAM) is an access management solution. Prior to 16.1.1, the OAuth 2.0 and OpenID Connect authorization endpoint does not sufficiently encode user-supplied parameters before FormPostResponse.ftl and checkSession.ftl render them into …
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High 7.0
OpenAM: Pre-authentication Reflected XSS in SAML2 Cluster Cookie-Hash-Redirect Path via `FSUtils.postToTarget`
Open Access Management (OpenAM) is an access management solution. Prior to 16.1.1, certain federation endpoints in a non-default clustered configuration inconsistently encode user-supplied parameters rendered into HTML in the SAML2 cluster cookie-hash redirec…
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High 7.3
Concrete CMS before 9.5.3 is vulnerable to Stored XSS in the YouTube block (vWidth/vHeight)
Concrete CMS before 9.5.3 applied only trim() to the YouTube block's stored width and height values and printed them into iframe HTML attributes without escaping or integer casting, resulting in stored cross-site scripting. A user with edit_block permission c…
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High 7.3CVE-2026-18116 Public exploit
Concrete CMS 8.3.0 to 9.5.2 is vulnerable to Stored XSS in Calendar Event Name via Workflow Approval Notifications
Concrete CMS 8.3.0 to 9.5.2 stored calendar event names without sanitization and rendered them without HTML escaping in the workflow approval and deletion notifications shown in the dashboard "Waiting For Me" block. A registered user permitted to add events t…
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High 7.3
Concrete CMS 9.0.0 to 9.5.2 is vulnerable to Stored XSS in Custom Page Alias Name
Concrete CMS 9.0.0 through 9.5.3 is vulnerable to stored XSS via the custom page alias name (customAliasName) because the Edit Alias dialog applied only trim() to the submitted value and performed no input neutralization. An authenticated user holding canWrit…
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High 7.0
Concrete CMS 9.0.0 to 9.5.2 is vulnerable to Stored XSS via Page Container icon
Concrete CMS versions 9.0.0 to 9.5.2 stored the Page Container icon value submitted through the dashboard without validating it against the set of known container icons. The unvalidated value was later concatenated into the src attribute of an img tag by a he…
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High 7.0
Concrete CMS below 9.5.3 is vulnerable to Stored XSS via unsanitized inline block custom style values
Concrete CMS below 9.5.3 did not sanitize custom style values in the Block Design dialog before writing them into page CSS via a DOM sink, permitting stored cross-site scripting. An editor-level user could execute script in an administrator's session and esca…
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High 7.6
EasyAdmin: Stored Cross-Site Scripting (XSS) via uploaded files served inline in FileField and ImageField
EasyAdmin is a fast and modern admin generator for Symfony applications. From 5.0.0 until 5.0.13, FileField and ImageField can accept browser-executable uploads while templates/crud/field/file.html.twig links to stored files for inline same-origin rendering w…
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High 8.7
parallax filament-comments through 3.0.0 Stored XSS via Comment Body
parallax filament-comments through 3.0.0 contains a stored cross-site scripting vulnerability in comment body rendering that allows authenticated panel users to inject malicious scripts. Attackers can store XSS payloads in comment bodies that execute in the b…
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High 7.5
Joomla Extension - regularlabs.com - Privileged stored XSS via url option in Snippets Free extension for Joomla < 7.0.0, Snippets Pro extension for Joomla < 11.0.0
Joomla Extension - regularlabs.com - Privileged stored XSS via url option in Snippets Free extension for Joomla < 7.0.0, Snippets Pro extension for Joomla < 11.0.0 - Snippets substitutes variable values supplied by an article tag into saved Snippet content. T…
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High 7.5
Joomla Extension - regularlabs.com - Privileged stored XSS via class option in Quick Index extension for Joomla < 5.0.5
Joomla Extension - regularlabs.com - Privileged stored XSS via class option in Quick Index extension for Joomla < 5.0.5 - Quick Index inserts configurable class values into generated HTML without escaping them for an HTML attribute. A crafted value can close …
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High 7.5
Joomla Extension - regularlabs.com - Privileged stored XSS via executable URL schemes in Modals extension for Joomla < 17.0.0
Joomla Extension - regularlabs.com - Privileged stored XSS via executable URL schemes in Modals extension for Joomla < 17.0.0 - Modals treats a destination using an executable browser URL scheme as an ordinary modal URL. The value can reach both the generated…
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High 7.5
Joomla Extension - regularlabs.com - Privileged stored XSS via link option in Articles Anywhere extension for Joomla < 20.0.0
Joomla Extension - regularlabs.com - Privileged stored XSS via link option in Articles Anywhere extension for Joomla < 20.0.0 - Articles Anywhere accepts link options such as onclick and onmouseover. In affected versions, those options become real HTML event …
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High 7.5
Joomla Extension - regularlabs.com - Privileged stored XSS via event handler option in Modals Pro extension for Joomla < 17.0.0
Joomla Extension - regularlabs.com - Privileged stored XSS via event handler option in Modals Pro extension for Joomla < 17.0.0 - Modals Pro intentionally supports JavaScript Events such as on-open and on-closed. Affected versions do not distinguish trusted e…
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High 7.5
Joomla Extension - regularlabs.com - Privileged stored XSS via rtla-alias option in Tabs & Accordions extension for Joomla < 3.1.0
Joomla Extension - regularlabs.com - Privileged stored XSS via rtla-alias option in Tabs & Accordions extension for Joomla < 3.1.0 - Tabs & Accordions rewrites links matching an item alias into calls to its browser API. The affected renderer places the alias …
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High 7.2
A bodyclass XSS issue was discovered in Paessler PRTG before 23.3.86.1520.
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High 8.8
YouTube Embed 10.0 - 10.3 - Unauthenticated Stored XSS via youram_server
The YouTube Embed WordPress plugin from 10.0 to 10.3 does not perform any authorisation check on one of its AJAX actions, relying only on a nonce it prints on every front-end page, and does not escape the stored data before rendering it, allowing unauthentica…
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High 8.8
Hoo Companion 1.0.2 - Unauthenticated Stored XSS via Theme Settings Import
The Hoo Companion WordPress plugin 1.0.2 does not have any authorisation or validation checks in one of its import features, and does not sanitise the data submitted to it before storing it as the active theme's settings, allowing unauthenticated attackers to…
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High 7.6
Amundsen Frontend through 4.3.0 Stored XSS via Description
Amundsen frontend through 4.3.0 renders table, dashboard, and feature descriptions with dangerouslySetInnerHTML without HTML sanitization in ResourceListItem components. Attackers can inject malicious markup like img elements with onerror handlers into descri…
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High 8.7
Strapi 4.x through 4.26.2 and 5.x before 5.48.1 Stored XSS via WYSIWYG
Strapi versions 4.x through 4.26.2 and 5.x before 5.48.1 contain a stored cross-site scripting vulnerability in the content manager WYSIWYG preview component that fails to strip script tags from rich text. An Author-role user can store malicious script tags i…
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High 8.0
YayPricing < 3.5.7 - Subscriber+ Stored XSS via save_page_data REST Route
The YayPricing WordPress plugin before 3.5.7 does not perform an authorization check on a REST route that saves its pricing rules, allowing users with the subscriber role and above to store JavaScript that executes in the browser of an administrator who opens…
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High 7.1
Export & Import WPBakery Page Builder <= 1.0.2 - Stored XSS via CSRF
The Export & Import WPBakery Page Builder WordPress plugin through 1.0.2 does not perform any CSRF check on its template-import feature and does not sanitise the imported data before storing it and echoing it back, allowing attackers to make a logged-in admin…
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High 8.8
BE REST Endpoints <= 1.0.0 - Unauthenticated Stored XSS and Widget Manipulation
The BE REST Endpoints WordPress plugin through 1.0.0 does not perform any authorization check before allowing widgets to be read, created, updated and deleted, and does not sanitize the values it stores in them, allowing unauthenticated users to inject arbitr…
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High 8.7
AVideo LoginControl Stored XSS via PGP Public Key
AVideo through commit c3edcc274c389816d434acadac07ee78eaf330c1 contains a stored cross-site scripting vulnerability in the LoginControl plugin that fails to HTML-encode PGP public keys echoed into a textarea element. An authenticated attacker can inject malic…
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High 8.7
AVideo Bookmark Plugin Stored XSS via Chapter Names
AVideo through commit c3edcc274c389816d434acadac07ee78eaf330c1 contains a stored cross-site scripting vulnerability in the Bookmark plugin where chapter names are not encoded before being concatenated into public watch-page HTML. A video owner can inject mali…
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High 8.7
AVideo CustomizeUser Stored XSS via field_name Parameter
AVideo through commit c3edcc274c389816d434acadac07ee78eaf330c1 contains a stored cross-site scripting vulnerability in the CustomizeUser plugin where the field_name parameter is stored raw without sanitization. Administrators can inject malicious scripts via …
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High 8.7
AVideo Stored XSS via donationLink in watch page button
WWBN AVideo through commit c3edcc274c389816d434acadac07ee78eaf330c1 contains a stored cross-site scripting vulnerability in the user 'donationLink' profile field. User::setDonationLink() (objects/user.php) stores the value and save() validates it only with fi…
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High 8.7
AVideo YPTWallet Stored XSS via CryptoWallet Configuration
AVideo through commit c3edcc274c389816d434acadac07ee78eaf330c1 contains a stored cross-site scripting vulnerability in the YPTWallet plugin where user-supplied CryptoWallet values are base64-encoded but not HTML-escaped before storage in wallet_log.informatio…
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High 8.1
WWBN AVideo Stored XSS via UserGroups setGroup_name
WWBN AVideo through commit c3edcc274c389816d434acadac07ee78eaf330c1 contains a stored cross-site scripting vulnerability in UserGroups::setGroup_name() that fails to sanitize group_name input. Administrators with canAdminUserGroups permission can inject malic…
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High 7.2
Kirki <= 6.2.0 - Unauthenticated Stored Cross-Site Scripting via 'comment' Parameter
The Kirki – Freeform Page Builder, Website Builder & Customizer plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the ‘comment’ parameter in all versions up to, and including, 6.2.0 due to insufficient input sanitization and output escapin…