What is CVE-2026-57434?

CVE-2026-57434 is a high-severity vulnerability in Nokogiri, classified under NULL Pointer Dereference. CVSS score: 7.5/10. Published 2026-06-25.

How severe is CVE-2026-57434?

High severity. CVSS v3 base score is 7.5 out of 10.

NULL pointer dereference in Nokogiri

CVE-2026-57434

Nokogiri is an open source XML and HTML library for the Ruby programming language. Prior to 1.19.4, Nokogiri contains a bug when calling certain methods on allocated-but-uninitialized native wrapper classes that inherit from Nokogiri::XML::Node. This caused a NULL pointer dereference that could crash the process. This vulnerability is fixed in 1.19.4.

Published 2026-06-25 · last modified 2026-06-26.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.005 (37.4th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 37th percentile — 37.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: 0.000

Affected products

Nokogiri
Sparklemotion Nokogiri — versions < 1.19.4

Weakness classification (CWE)

CWE-476 — NULL Pointer Dereference

References

github.com/sparklemotion/nokogiri/security/advisories/GHSA-9cv2-cfxc-v4v2 (Mitigation, Vendor Advisory)

Frequently asked questions

What is CVE-2026-57434?: CVE-2026-57434 is a high-severity vulnerability in Nokogiri, classified under NULL Pointer Dereference. CVSS score: 7.5/10. Published 2026-06-25.
How severe is CVE-2026-57434?: High severity. CVSS v3 base score is 7.5 out of 10.