CVE-2021-37700

Clipboard-based DOM-XSS

MEDIUM
6.1
CVSS Score
Published: August 12, 2021 at 08:45 PM UTC
Updated: June 17, 2026 at 04:01 AM UTC
2 products affected across 2 vendorsPaste MarkdownMarkdown Project Paste Markdown

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Severity
MEDIUM6.1
Exploit prediction
EPSS 2%

Description

@github/paste-markdown is an npm package for pasting markdown objects. A self Cross-Site Scripting vulnerability exists in the @github/paste-markdown before version 0.3.4. If the clipboard data contains the string `<table>`, a **div** is dynamically created, and the clipboard content is copied into its **innerHTML** property without any sanitization, resulting in improper execution of JavaScript in the browser of the victim (the user who pasted the code). Users directed to copy text from a malicious website and paste it into pages that utilize this library are affected. This is fixed in version 0.3.4. Refer the to the referenced GitHub Advisory for more details including an example exploit.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 0.3.4
Affected range stops below 0.3.4, so it looks safe — our inference, not a vendor statement
v < 0.3.4
Affected range stops below 0.3.4, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
REQUIRED
Scope
CHANGED
Confidentiality
LOW
Integrity
LOW
Availability
NONE
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-79

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