Medium [CVE-2026-57234] Server-Side Request Forgery (SSRF) and XML External Entity (XXE) via improper enforcement of NONET parse option
This medium-severity Red Hat Linux advisory covers CVE-2026-57234.
Aggregated and source-linked by VulniPulse. Data sources, validation and limitations.
VulniPulse record published Record updated
Summary
Nokogiri is an open source XML and HTML library for the Ruby programming language. Prior to 1.19.4, the NONET parse option, which Nokogiri turns on by default for Nokogiri::XML::Schema (see CVE-2020-26247), was not correctly enforced on the JRuby implementation.
As a result, a schema parsed with default options could still cause external resources to be fetched over the network, potentially enabling SSRF or XXE attacks. This vulnerability is fixed in 1.19.4.
This oversight could allow a specially crafted XML schema to fetch external resources over the network, potentially leading to Server-Side Request Forgery (SSRF) or XML External Entity (XXE) attacks. Red Hat products are not affected by this vulnerability.
Red Hat products use the CRuby (MRI) implementation, where NONET is correctly enforced and external resource fetching is properly blocked. Red Hat severity: Low — CVSS 4.8 (CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:N/A:N).
Weakness: CWE-611. Red Hat lists Red Hat 3scale API Management Platform 2; Red Hat Satellite 6 as not affected.
Is CVE-2026-57234 exploited?
No exploitation is reported in the sources VulniPulse tracks: CVE-2026-57234 is not in the CISA KEV catalog (checked ) and this advisory does not report exploitation. That is not proof the vulnerability cannot be exploited.
How do I fix CVE-2026-57234?
Upgrade to a fixed release named by Red Hat:
- 1.19.4
Confirm against the vendor advisory before you patch.
- < 1.19.4
Official advisory · high-confidence parse· fetched 14 days ago·verify at source
Mitigation checklist
- Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
Official advisory · high-confidence parse· fetched 14 days ago·verify at source
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