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

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.

Published: 2025-11-10 Last update: 2026-04-15 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2025-64501 is rated Low Risk (32.6/100): CVSS High severity, with low exploitation likelihood (EPSS 0.02%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2025-64501

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-04-08 0.06% 0.02% -0.04%
2 2026-03-12 0.03% 0.06% +0.03%
3 2025-11-11 0.03%

Full EPSS history (3 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-64501

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.6 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
2.3 4.7 [email protected]

Weakness enumeration for CVE-2025-64501

GitHub Security Advisory for CVE-2025-64501

GHSA-52c5-vh7f-26fx · Severity: high · Ecosystem: rubygems — Cross-Site Scripting (XSS) vulnerability through unescaped HTML attribute values

Affected software / configurations for CVE-2025-64501

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2025-64501

cvelogic Threat Intelligence