CVE-2026-57438 Nokogiri: Possible Use-After-Free in XInclude Processing
An attacker can trigger a use-after-free in Nokogiri's XInclude processing, potentially leading to memory corruption or crashes.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-57438?
CVE-2026-57438 is a low-severity use after free vulnerability in sparklemotion nokogiri, published on 25 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
Nokogiri is an open source XML and HTML library for the Ruby programming language. Prior to 1.19.4, XInclude substitution performed by Nokogiri::XML::Node#do_xinclude replaced each <xi:include> in place, freeing the include node along with its children (such as <xi:fallback> and its descendants) and any namespaces declared on them. If an application had already exposed one of those nodes or namespaces to Ruby, the corresponding Ruby object was left pointing at freed memory. Using the object could result in invalid reads or writes to memory. This vulnerability is fixed in 1.19.4.
Weakness: CWE-416
Which versions are affected by CVE-2026-57438?
2 open source packages ship an affected version, including nokogiri. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
nokogiri RubyGems | All versions | 1.19.4 |
nokogiri RubyGems | All versions | 1.19.4 |
Products include Nokogiri Nokogiri.
How do I fix CVE-2026-57438?
Upgrade nokogiri to 1.19.4 or later.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-57438 being exploited?
There is no known exploitation of CVE-2026-57438 in the wild and no public exploit code.
Other vulnerabilities in sparklemotion nokogiri
- CVE-2026-79770 Nokogiri before 1.19.3 ReDoS via CSS selector tokenizer
- CVE-2022-23476 Unchecked return value from xmlTextReaderExpand in Nokogiri
- CVE-2021-41098 Improper Restriction of XML External Entity Reference (XXE) in Nokogiri on JRuby
- CVE-2012-6685 Nokogiri is vulnerable to XML External Entity (XXE) attack
- CVE-2026-79771 Nokogiri before 1.19.3 Memory Leak via XSLT Transform
Sources
Also known as AZL-91062, BELL-CVE-2026-57438, CLEANSTART-2026-EZ51982, DEBIAN-CVE-2026-57438, GHSA-wfpw-mmfh-qq69, MINI-526p-87jf-54cp and 8 more.