Vulnerability · Published Nov 10, 2025 · Assigned by GitHub_M

CVE-2025-64501ProsemirrorToHtml: Cross-Site Scripting vulnerability through unescaped HTML attribute values

High 7.6

In plain English

A high-severity cross-site scripting in prosemirror_to_html from etaminstudio. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 15% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.6High

Exploit odds (30 days)0.2%top 85.2% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
RubyGems	prosemirror_to_html	0.2.1	GHSA-52c5-vh7f-26fx

Affected products (as reported)

Vendor	Product	Versions
etaminstudio	prosemirror_to_html	< 0.2.1

Weakness: CWE-79 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:L/A:N

References

https://github.com/etaminstudio/prosemirror_to_html/security/advisories/GHSA-52c5-vh7f-26fx x_refsource_CONFIRM
https://github.com/etaminstudio/prosemirror_to_html/commit/4d59f94f550bcabeec30d298791bbdd883298ad8 x_refsource_MISC