Weaknesses of type CWE-87

55 results

Neutralização inadequada de sintaxe alternativa de XSS

A aplicação tenta bloquear ataques XSS filtrando apenas as formas mais óbvias (como <script>), mas não neutraliza variações alternativas da sintaxe HTML/JavaScript que achievem o mesmo resultado. Atacantes usam event handlers (onclick, onerror), protocolos (javascript:), ou tags menos conhecidas (svg, iframe) para injetar código malicioso que o filtro deixa passar.

Example

Um site bloqueia a tag <script> mas aceita <img src=x onerror='alert(1)'>, ou filtra javascript: mas não bloqueia JaVaScRiPt: (variação de caso). Outra variação comum: bloquear <svg onload> mas não <svg><animate onbegin=alert(1)>.

How to mitigate

Use biblioteca anti-XSS consolidada (DOMPurify, OWASP HTML Sanitizer) que trata todas as variações, não filtros caseiros. Melhor ainda: escapeie saídas HTML conforme contexto (HTML entity encoding para conteúdo, atributo encoding para atributos) em vez de tentar listar ataques conhecidos. Valide no servidor e aplique Content Security Policy (CSP) como segunda camada.

CVE-2026-40321HIGHDotNetNuke.Core has stored cross-site-scripting (XSS) via SVG uploadEPSS 7.6%CVE-2023-35161CRITICALXWiki Platform vulnerable to reflected cross-site scripting via xredirect parameter in DeleteApplication pageEPSS 2.4%CVE-2023-35160CRITICALXWiki Platform vulnerable to reflected cross-site scripting via back and xcontinue parameters in resubmit templateEPSS 2.3%CVE-2023-35159CRITICALXWiki Platform vulnerable to reflected cross-site scripting via xredirect parameter in deletespace templateEPSS 2.2%CVE-2023-35156CRITICALXWiki Platform vulnerable to reflected cross-site scripting via xredirect parameter in delete templateEPSS 2.1%CVE-2023-35158CRITICALXWiki Platform vulnerable to reflected cross-site scripting via xredirect parameter in restore templateEPSS 2.0%CVE-2022-36033MEDIUMjsoup may not sanitize Cross-Site Scripting (XSS) attempts if SafeList.preserveRelativeLinks is enabledEPSS 1.2%CVE-2020-5298MEDIUMReflected XSS when importing CSV in OctoberCMSEPSS 0.9%CVE-2021-40131MEDIUMCisco Common Services Platform Collector Stored Cross-Site Scripting VulnerabilityEPSS 0.7%CVE-2022-39295MEDIUMImproper Neutralization of Alternate XSS Syntax in Knowage-ServerEPSS 0.5%CVE-2025-54369CRITICALNode-SAML SAML Authentication BypassEPSS 0.5%CVE-2023-20188MEDIUMA vulnerability in the web-based management interface of Cisco Small Business 200 Series Smart Switches, Cisco Small Business 300 Series ManEPSS 0.5%CVE-2025-27793MEDIUMVega vulnerable to Cross-site Scripting via RegExp.prototype[@@replace]EPSS 0.5%CVE-2026-33506HIGHDOM-Based XSS in Ory Polis Login PageEPSS 0.5%CVE-2023-20208MEDIUMA vulnerability in the web-based management interface of Cisco ISE could allow an authenticated, remote attacker to conduct an XSS attack agEPSS 0.5%CVE-2024-43381MEDIUMreNgine vulnerable to Stored Cross-Site Scripting (XSS) via DNS Record PoisoningEPSS 0.4%CVE-2022-20963MEDIUMA vulnerability in the web-based management interface of Cisco Identity Services Engine (ISE) could allow an authenticated, remote attacker EPSS 0.4%CVE-2026-54002HIGHKirby: Cross-site scripting (XSS) from incomplete HTML/XML sanitization in `Dom::sanitize()`EPSS 0.4%CVE-2026-25688MEDIUMApache Answer: XSS in AI Answer RenderingEPSS 0.4%CVE-2024-8505MEDIUMWordPress Infinite Scroll - Ajax Load More <= 7.1.2 - Authenticated (Contributor+) Stored Cross-Site Scripting via button_label ParameterEPSS 0.4%