CVE-2025-64501

HIGH
Published Nov 10, 2025 Modified Apr 15, 2026 CWE-79

Description

ProsemirrorToHtml is a JSON converter which takes ProseMirror-compatible JSON and outputs HTML. In versions 0.2.0 and below, the `prosemirror_to_html` gem is vulnerable to Cross-Site Scripting (XSS) attacks through malicious HTML attribute values. While tag content is properly escaped, attribute values are not, allowing attackers to inject arbitrary JavaScript code. Applications that use `prosemirror_to_html` to convert ProseMirror documents to HTML, user-generated ProseMirror content, and end users viewing the rendered HTML output are all at risk of attack. This issue is fixed in version 0.2.1.

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CVSS v3.1 Score

7.6
HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:L/A:N

Weakness Type (CWE)

CWE-79 Cross-site Scripting (XSS)

References

Frequently Asked Questions

What is CVE-2025-64501? +
ProsemirrorToHtml is a JSON converter which takes ProseMirror-compatible JSON and outputs HTML. In versions 0.2.0 and below, the `prosemirror_to_html` gem is vulnerable to Cross-Site Scripting (XSS) attacks through malicious HTML attribute values. While tag content is properly escaped, attribute values are not, allowing attackers to inject arbitrary JavaScript code. Applications that use `prosemirror_to_html` to convert ProseMirror documents to HTML, user-generated ProseMirror content, and end users viewing the rendered HTML output are all at risk of attack. This issue is fixed in version 0.2.1. It has a CVSS v3.1 base score of 7.6 (HIGH).
How severe is CVE-2025-64501? +
CVE-2025-64501 has a CVSS v3.1 score of 7.6 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.
How do I check if I'm vulnerable to CVE-2025-64501? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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