Weakness (CWE)
CWE-80: Improper Neutralization of Script-Related HTML Tags in a Web Page
The product receives input from an upstream component, but it does not neutralize or incorrectly neutralizes special characters such as "<", ">", and "&" that could be interpreted as web-scripting elements when they are sent to a downstream component that processes web pages.
How to prevent it (4 mitigations)
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Implementation
Carefully check each input parameter against a rigorous positive specification (allowlist) defining the specific characters and format allowed. All input should be neutralized, not just parameters that the user is supposed to specify, but all data in the request, including hidden fields, cookies, headers, the URL itself, and so forth. A common mistake that leads to continuing XSS vulnerabilities is to validate only fields that are expected to be redisplayed by the site. We often encounter data from the request that is reflected by the application server or the application that the development team did not anticipate. Also, a field that is not currently reflected may be used by a future developer. Therefore, validating ALL parts of the HTTP request is recommended.
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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-80
25 results · Clear filters · Feed
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Critical 9.8
Vitess vttablet /twopcz reflected XSS
Vitess is a database clustering system for horizontal scaling of MySQL. Prior to 23.0.5 and 24.0.2, twopczHandler in go/vt/vttablet/tabletserver/twopcz.go writes the Action and dtid form values from the vttablet and vtcombo /twopcz HTTP debug endpoint into a …
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Critical 9.3
Home Assistant: XSS in Statistics Graph Card
Home Assistant is open source home automation software focused on local control and privacy. Prior to 2026.7.0, the Statistics Graph card in src/components/chart/statistics-chart.ts passed entity names through getStatisticLabel and computeStateName and interp…
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Critical 9.3
mailcow: dockerized vulnerable to stored XSS in autodiscover logs email address field
mailcow: dockerized is an open source groupware/email suite based on docker. In versions prior to 2026-03b, the admin dashboard's Autodiscover logs render the EMailAddress value (logged as the "user" field) without HTML escaping. By submitting an unauthentica…
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Critical 9.4
OpenBao has Reflected XSS in its OIDC authentication error message
OpenBao is an open source identity-based secrets management system. Prior to version 2.5.2, OpenBao installations that have an OIDC/JWT authentication method enabled and a role with `callback_mode=direct` configured are vulnerable to XSS via the `error_descri…
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Critical 9.1
Anchorr Privilege Escalation: Jellyseerr User → Anchorr Admin via Stored XSS
Anchorr is a Discord bot for requesting movies and TV shows and receiving notifications when items are added to a media server. Versions 1.4.1 and below contain a stored XSS vulnerability in the Jellyseerr user selector. Jellyseerr allows any account holder t…
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Critical 9.7
DeepChat's Incomplete XSS Fix Allows RCE through Mermaid Content
DeepChat is an open-source AI chat platform that supports cloud models and LLMs. Versions 0.5.1 and below are vulnerable to XSS attacks through improperly sanitized Mermaid content. The recent security patch for MermaidArtifact.vue is insufficient and can be …
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Critical 9.3
spacewalk-java has various XSS issues on search page
A Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS) vulnerability allows attackers to run arbitrary javascript via a reflected XSS issue in the search fields.This issue affects Container suse/manager/5.0/x86_64/server:latest: from …
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Critical 9.1
NamelessMC allows Stored Cross-Site Scripting (XSS) in dashboard text editor
NamelessMC is a free, easy to use & powerful website software for Minecraft servers. Cross-site scripting (XSS) vulnerability in NamelessMC before 2.2.3 allows remote authenticated attackers to inject arbitrary web script or HTML via the dashboard text editor…
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Critical 9.1
XWiki Rendering is vulnerable to XSS attacks through insecure XHTML syntax
XWiki Rendering is a generic rendering system that converts textual input in a given syntax (wiki syntax, HTML, etc) into another syntax (XHTML, etc). Starting in version 5.4.5 and prior to version 14.10, the XHTML syntax depended on the `xdom+xml/current` sy…
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Critical 9.6CVE-2024-39363 EPSS 49%
A cross-site scripting (xss) vulnerability exists in the login.cgi set_lang_CountryCode() functionality of Wavlink AC30…
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Critical 9.1
macro-pdfviewer has a XSS through the width parameter
macro-pdfviewer is a PDF Viewer Macro for XWiki using Mozilla pdf.js. The width parameter of the PDF viewer macro isn't properly escaped, allowing XSS for any user who can edit a page. XSS can impact the confidentiality, integrity and availability of the whol…
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Critical 9.1CVE-2024-41947 Public exploit
XWiki Platform XSS through conflict resolution
XWiki Platform is a generic wiki platform offering runtime services for applications built on top of it. By creating a conflict when another user with more rights is currently editing a page, it is possible to execute JavaScript snippets on the side of the ot…
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Critical 9.7CVE-2024-34070 Public exploit
Froxlor Vulnerable to Blind XSS Leading to Froxlor Application Compromise
Froxlor is open source server administration software. Prior to 2.1.9, a Stored Blind Cross-Site Scripting (XSS) vulnerability was identified in the Failed Login Attempts Logging Feature of the Froxlor Application. An unauthenticated User can inject malicious…
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Critical 9.7
Reflected Cross-site scripting through revision parameter in content menu in XWiki Platform
XWiki Platform is a generic wiki platform offering runtime services for applications built on top of it. XWiki is vulnerable to reflected cross-site scripting (RXSS) via the `rev` parameter that is used in the content of the content menu without escaping. If …
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Critical 9.3
Piwigo Reflected XSS vulnerability
Piwigo is an open source photo gallery application. Prior to version 14.0.0beta4, a reflected cross-site scripting (XSS) vulnerability is in the` /admin.php?page=plugins&tab=new&installstatus=ok&plugin_id=[here]` page. This vulnerability can be exploited by a…
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Critical 9.6
Improper input validation in Zoom Desktop Client for Windows before 5.14.7 may allow an unauthenticated user to enable …
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Critical 9.1
XWiki Platform vulnerable to stored cross-site scripting in ClassEditSheet page via name parameters
XWiki Platform is a generic wiki platform. Starting in version 5.4.4 and prior to versions 14.4.8, 14.10.4, and 15.0, a stored cross-site scripting vulnerability can be exploited by users with edit rights by adding a `AppWithinMinutes.FormFieldCategoryClass` …
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Critical 9.1
A stored cross-site scripting vulnerability exists in the HdConfigActions.aspx altertextlanguages functionality of Lans…
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Critical 9.6
Cross Site Scripting in Wire Messages
Wire is a secure messaging application. Wire is vulnerable to arbitrary HTML and Javascript execution via insufficient escaping when rendering `@mentions` in the wire-webapp. If a user receives and views a malicious message, arbitrary code is injected and exe…
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Critical 9.1CVE-2022-21145 EPSS 78%
A stored cross-site scripting vulnerability exists in the WebUserActions.aspx functionality of Lansweeper lansweeper 9.…
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Critical 10.0
Failure to Sanitize Special Elements into a Different Plane (Special Element Injection) in notebook
The Jupyter notebook is a web-based notebook environment for interactive computing. In affected versions untrusted notebook can execute code on load. Jupyter Notebook uses a deprecated version of Google Caja to sanitize user inputs. A public Caja bypass can b…
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Critical 9.6CVE-2020-13564 EPSS 76%
A cross-site scripting vulnerability exists in the template functionality of phpGACL 3.3.7. A specially crafted HTTP re…
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Critical 9.6CVE-2020-13563 EPSS 76%
A cross-site scripting vulnerability exists in the template functionality of phpGACL 3.3.7. A specially crafted HTTP re…
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Critical 9.6CVE-2020-13562 EPSS 78%
A cross-site scripting vulnerability exists in the template functionality of phpGACL 3.3.7. A specially crafted HTTP re…
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Critical 9.0
Stored cross-site scripting vulnerability in QES
If exploited, this stored cross-site scripting vulnerability could allow remote attackers to inject malicious code in File Station. QNAP has already fixed these issues in QES 2.1.1 Build 20201006 and later.