CVE-2025-66400
BaseFortify
Publication date: 2025-12-01
Last updated on: 2026-02-06
Assigner: GitHub, Inc.
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| syntax-tree | mdast-util-to-hast | From 13.0.0 (inc) to 13.2.1 (inc) |
| unifiedjs | mdast-util-to-hast | From 13.0.0 (inc) to 13.2.1 (inc) |
| mdast-util | mdast-util-to-hast | 13.2.1 |
| mdast-util | mdast-util-to-hast | 13.0.0 |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-915 | The product receives input from an upstream component that specifies multiple attributes, properties, or fields that are to be initialized or updated in an object, but it does not properly control which attributes can be modified. |
| CWE-20 | The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability in mdast-util-to-hast versions from 13.0.0 to before 13.2.1 allows multiple unprefixed classnames to be added in markdown source by using character references. This means that user-supplied markdown code elements could be made to appear like the rest of the page, potentially misleading users about the origin or nature of the content. The issue was fixed in version 13.2.1.
How can this vulnerability impact me? :
The vulnerability could allow an attacker to manipulate the appearance of user-supplied markdown code elements so that they look like legitimate parts of the page. This could lead to confusion or deception, potentially enabling phishing or other social engineering attacks by making malicious content appear trustworthy or integrated with the rest of the page.
What immediate steps should I take to mitigate this vulnerability?
Update mdast-util-to-hast to version 13.2.1 or later, as this version contains the fix for the vulnerability.