Quick answers
- Is CVE-2026-57434 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-57434 being exploited in the wild.
- How severe is CVE-2026-57434?
- Medium severity, with a CVSS score of 4, published 25 June 2026.
- Which products and versions are affected?
- nokogiri (RubyGems) ECOSYSTEM:introduced=0,fixed=1.19.4.
- Is there a fix for CVE-2026-57434?
- Yes. nokogiri (RubyGems): upgrade to 1.19.4 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-57434 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-57434?
- Check whether you run nokogiri (RubyGems) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
How to fix
- nokogiri (RubyGems): upgrade to 1.19.4 or later
bundle update nokogiri
Technical details
A NULL pointer dereference exists in Nokogiri's native wrapper classes inheriting from Nokogiri::XML::Node. The vulnerability is triggered when application code calls .allocate directly on a native-backed class and subsequently invokes methods on the resulting uninitialized object before proper initialization. This results in a crash of the Ruby process. The issue is limited to CRuby implementations; JRuby is not affected. A fix is available in version 1.19.4, which adds checks for missing native data pointers and raises a RuntimeError instead of crashing.
Affected products
- sparklemotion Nokogiri < 1.19.4
Identifiers
- CVE-2026-57434
- GHSA-9cv2-cfxc-v4v2
Timeline
- 2026-06-18: advisory: GitHub Security Advisory published by maintainers
- 2026-06-25: disclosed: CVE published to NVD