jsondiffpatch is vulnerable to Cross-site Scripting (XSS) via HtmlFormatter::nodeBegin
Date: 2025-09
Affected: npm/jsondiffpatch
Attack vector: xss
Category: vulnerability-disclosure
Severity: Medium
CVE: CVE-2025-9910
CWE: CWE-79
CVSS: 4.7 (CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N)

### Vulnerability in jsondiffpatch Versions of `jsondiffpatch` prior to `0.7.2` are vulnerable to Cross-site Scripting (XSS) in the `HtmlFormatter` (`HtmlFormatter::nodeBegin`). When diffs are rendered to HTML using the built-in formatter, untrusted payloads can inject scripts and execute in the context of a consuming web page. **Affected versions:** >= 0, < 0.7.2 **Patched version:** 0.7.2 **Remediation** Upgrade to `jsondiffpatch` `0.7.2` or later. The fix hardens the HTML formatter to avoid script injection. **Workarounds** Avoid using the HTML formatter on untrusted diffs, or sanitize/escape the rendered output.


Mitigations:

Architectural layers (MAESTRO):