CVE-2025-64501: Cross-Site Scripting (XSS) vulnerability through unescaped HTML attribute values

CVE-2025-64501 · Severity: high · CVSS 7.6 · Published 2025-11-10

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.

Technologies: prosemirror_to_html (RubyGems). Vendors: RubyGems.

Quick answers

Is CVE-2025-64501 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2025-64501 being exploited in the wild.
How severe is CVE-2025-64501?
High severity, with a CVSS score of 7.6, published 10 November 2025.
Which products and versions are affected?
prosemirror_to_html (RubyGems) ECOSYSTEM:introduced=0,fixed=0.2.1.
Is there a fix for CVE-2025-64501?
Yes. prosemirror_to_html (RubyGems): upgrade to 0.2.1 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
Am I affected by CVE-2025-64501?
Check whether you run prosemirror_to_html (RubyGems) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • prosemirror_to_html (RubyGems): upgrade to 0.2.1 or later
    bundle update prosemirror_to_html

Affected products

  • prosemirror_to_html (RubyGems) ECOSYSTEM:introduced=0,fixed=0.2.1

Identifiers

  • CVE-2025-64501
  • GHSA-52c5-vh7f-26fx

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