How severe is CVE-2026-57434?

CVE-2026-57434 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2026-57434 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (28th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-57434?

CVE-2026-57434 affects Nokogiri. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-57434?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-57434 have an EU (EUVD) identifier?

Yes. CVE-2026-57434 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-39424.

When was CVE-2026-57434 published?

CVE-2026-57434 was published on 2026-06-25 and last updated on 2026-06-26.

CVE-2026-57434

CVE-2026-57434 is a high-severity vulnerability in Nokogiri with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-476.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v4: 1.7
EPSS exploit prediction: 0% (28th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-39424
Weakness: CWE-476
Affected product: Nokogiri
Published: 2026-06-25
Last modified: 2026-06-26

Description

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.

Frequently asked questions

What is 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.
How severe is CVE-2026-57434?: CVE-2026-57434 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2026-57434 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (28th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-57434?: CVE-2026-57434 affects Nokogiri. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-57434?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-57434 have an EU (EUVD) identifier?: Yes. CVE-2026-57434 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-39424.
When was CVE-2026-57434 published?: CVE-2026-57434 was published on 2026-06-25 and last updated on 2026-06-26.

References

https://github.com/sparklemotion/nokogiri/security/advisories/GHSA-9cv2-cfxc-v4v2

Affected products (1)

cpe:2.3:a:nokogiri:nokogiri:*:*:*:*:*:ruby:*:*

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