Dompurify
CVE-2020-26870
MEDIUM
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A05:2025 - Injection
ASVS 5.0
V1 - Encoding and Sanitization Output encoding, context-aware escaping
MITRE ATT&CK
2 techniques across 2 tactics: Initial Access, Execution The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Impact | CVSS score of 6.1 (MEDIUM). Attack characteristics: network attack vector, low complexity, no privileges required, user interaction required. Public proof-of-concept exploit code is available. |
| Exploit ScenarioDerived | A remote attacker could inject malicious scripts into web pages viewed by other users by sending crafted requests to the affected application. No authentication is required to exploit this vulnerability. |
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Alert meAnalysisAI
Cure53 DOMPurify before 2.0.17 allows mutation XSS. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.
RemediationAI
A vendor patch is available. Apply the latest security update as soon as possible. Sanitize all user input, use Content-Security-Policy headers, encode output contextually (HTML, JS, URL). Use frameworks with built-in XSS protection.
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 1 package in npm
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
This vulnerability is classified as Cross-Site Scripting (XSS) (CWE-79), which allows attackers to inject malicious scripts into web pages viewed by other users. Cure53 DOMPurify before 2.0.17 allows mutation XSS. This occurs because a serialize-parse roundtrip does not necessarily return the original DOM tree, and a namespace can change from HTML to MathML, as demonstrated by nesting of FORM elements. Affected products include: Cure53 Dompurify, Debian Debian Linux, Microsoft Visual Studio 2017, Microsoft Visual Studio 2019, Oracle Application Express. Version information: before 2.0.17.
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- Exploit and PoC references, threat intelligence from 22 sources
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Severity by source
AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
DescriptionNVD
Cure53 DOMPurify before 2.0.17 allows mutation XSS. This occurs because a serialize-parse roundtrip does not necessarily return the original DOM tree, and a namespace can change from HTML to MathML, as demonstrated by nesting of FORM elements.
Threat Intelligence Overview
NVD
CVE.org
EPSS
GitHub
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Cross-Site Scripting occurs when an application accepts untrusted data and sends it to a web browser without proper validation or encoding.
Affected Products (CPE)NVD
DOMPurify is a DOM-only, super-fast, uber-tolerant XSS sanitizer for HTML, MathML and SVG. Rated medium severity (CVSS 6
DOMPurify before 2.0.1 allows XSS because of innerHTML mutation XSS (mXSS) for an SVG element or a MATH element, as demo
DOMPurify is a DOM-only, super-fast, uber-tolerant XSS sanitizer for HTML, MathML and SVG. Rated critical severity (CVSS
Mutation-XSS in DOMPurify before 3.3.2 enables JavaScript execution in victim browsers when sanitized output is re-inser
Hook mutation pollution in DOMPurify <= 3.4.5 allows persistent bypass of HTML sanitization defaults when application-in
Trusted Types policy state contamination in DOMPurify 3.0.0-3.4.8 allows a previously supplied TRUSTED_TYPES_POLICY to s
Prototype pollution in DOMPurify's USE_PROFILES mode enables DOM-based XSS by causing the sanitizer to accept event hand
URI validation bypass in DOMPurify 3.3.1 and earlier allows `javascript:` protocol payloads to survive HTML sanitization
SAFE_FOR_TEMPLATES bypass in DOMPurify 3.0.0-3.4.7 allows template expressions such as ${evil}, {{evil}}, and <%evil%> t
Cross-site scripting in DOMPurify 3.4.6 and earlier enables script execution when the library's IN_PLACE sanitization mo
Stored XSS is achievable in applications using DOMPurify's setConfig() API combined with an uponSanitizeAttribute hook t
DOMPurify before 3.2.4 has an incorrect template literal regular expression, sometimes leading to mutation cross-site sc
Exploit-DB