Skip to content
VulniPulse
Sign in
Advisory severityMedium6.5Red Hat Linux

Medium [CVE-2026-57236] Denial of Service or Information Disclosure via invalid encoding handling

This medium-severity Red Hat Linux advisory covers CVE-2026-57236 affecting Red Hat Satellite 6.16 for RHEL 8, Red Hat Satellite 6.16 for RHEL 9, Red Hat Satellite 6.17 for RHEL 9.

Aggregated and source-linked by VulniPulse. Data sources, validation and limitations.

CVE-2026-57236 Source published Source updated

VulniPulse record published Record updated

CVE-2026-57236
Affected products & platforms
Red Hat LinuxUnclassified
Open source advisory

Summary

Nokogiri is an open source XML and HTML library for the Ruby programming language. Prior to 1.19.4, calling Document#encoding= with an invalid encoding (e.g., a non-string, or a string containing a null byte) raises an exception, but only after freeing the document's current encoding string without replacing it.

The document is left referencing freed memory, so the next call to Document#encoding reads invalid memory, which can cause a segfault or leak freed bytes into a Ruby String. Affects the CRuby (libxml2) implementation only; JRuby is not affected.

This vulnerability is fixed in 1.19.4. This leaves the document referencing freed memory, which can lead to a denial of service (DoS) due to a segmentation fault or information disclosure by leaking freed memory into a Ruby String.

This flaw has an Important impact as Nokogiri's CRuby implementation in Red Hat products is vulnerable to a use-after-free when processing invalid encoding values. Red Hat severity: Moderate — CVSS 6.5 (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:H).

Weakness: CWE-825. Affected Red Hat products: Red Hat Satellite 6.16 for RHEL 8; Red Hat Satellite 6.16 for RHEL 9; Red Hat Satellite 6.17 for RHEL 9; Red Hat Satellite 6.18 for RHEL 9; Red Hat Satellite 6.19 for RHEL 9; Red Hat Satellite 6.

Red Hat fixing advisory: RHSA-2026:50223, RHSA-2026:50222, RHSA-2026:50263, RHSA-2026:50221.

Is CVE-2026-57236 exploited?

No exploitation is reported in the sources VulniPulse tracks: CVE-2026-57236 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-2026-57236?

Upgrade to a fixed release named by Red Hat:

  • 1.19.4
  • rubygem-nokogiri-0:1.15.7-3.el8sat
  • rubygem-nokogiri-0:1.15.7-3.el9sat
  • rubygem-nokogiri-0:1.17.2-3.el9sat
  • RHSA-2026:50223
  • RHSA-2026:50222
  • RHSA-2026:50263
  • RHSA-2026:50221

Confirm against the vendor advisory before you patch.

Affected versions
  • < 1.19.4

Official advisory · high-confidence parse· fetched 14 days ago·verify at source

Fixed versions
  • 1.19.4
  • rubygem-nokogiri-0:1.15.7-3.el8sat
  • rubygem-nokogiri-0:1.15.7-3.el9sat
  • rubygem-nokogiri-0:1.17.2-3.el9sat
  • RHSA-2026:50223
  • RHSA-2026:50222
  • RHSA-2026:50263
  • RHSA-2026:50221

Official advisory · high-confidence parse· fetched 14 days ago·verify at source

Mitigation checklist

Recommended fix / mitigation
  • 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

Get an email when Red Hat publishes the next one.

See Red Hat's last 90 days of advisories first. Then choose one product with live alerts free for life, or a free month of real-time alerts on everything with the severity, the fixed version and the vendor's link (card needed, then US$15/month; we email you before the first charge).

Alert me about Red Hat

More Red Hat Linux advisories

All Red Hat Linux advisories

iPhone and Android apps · New on the App Store

Monitor future Red Hat Linux CVEs from your phone.

Choose a whole vendor or a precise platform, then receive matching security advisories by phone notification, email, or both. Coverage follows 34 official vendor sources and 160+ reviewed platform categories.

Download on the App StoreGet CVE alerts on AndroidSee app features

Discussion(0)

No comments yet. Share field notes, upgrade gotchas, or questions — verify against the vendor advisory before acting on community advice.

Sign in to join the discussion.