Cyber Resilience

CVE-2026-57234

XXE in Nokogiri ≤ 1.19.4

XXE
Published
25 June 2026
Modified
26 June 2026
Patch / advisory
View advisory
CVSS Score v3.1 2.6
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:L/I:N/A:N
EPSS Score 0.0017 6th percentile
Risk Priority 23 floored blend · peak EPSS

Summary

CVE-2026-57234 is a low-severity Improper Handling of Case Sensitivity (CWE-178) vulnerability in Nokogiri Nokogiri. Its CVSS base score is 2.6 (Low).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 6th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to CM-6 (Configuration Settings) and SA-11 (Developer Testing and Evaluation) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

A02:2025 Security Misconfiguration

EU & UK References

Vulnerability Data

Nokogiri is an open source XML and HTML library for the Ruby programming language. Prior to 1.19.4, the NONET parse option, which Nokogiri turns on by default for Nokogiri::XML::Schema (see CVE-2020-26247), was not correctly enforced on the JRuby implementation. As…

more

a result, a schema parsed with default options could still cause external resources to be fetched over the network, potentially enabling SSRF or XXE attacks. This vulnerability is fixed in 1.19.4.

CWE(s)
CWE-178CWE-184CWE-611

Related Threats

MITRE ATT&CK Enterprise Techniques

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1005 Data from Local System Collection
Adversaries may search local system sources, such as file systems, configuration files, local databases, virtual machine files, or process memory, to find files of interest and sensitive data prior to Exfiltration.
attack.mitre.org →
T1036 Masquerading Stealth
Adversaries may attempt to manipulate features of their artifacts to make them appear legitimate or benign to users and/or security tools.
attack.mitre.org →
T1213 Data from Information Repositories Collection
Adversaries may leverage information repositories to mine valuable information.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-57437Same product: Nokogiri Nokogiri
CVE-2026-57236Same product: Nokogiri Nokogiri
CVE-2026-57435Same product: Nokogiri Nokogiri
CVE-2026-57436Same product: Nokogiri Nokogiri
CVE-2026-57235Same product: Nokogiri Nokogiri
CVE-2026-57434Same product: Nokogiri Nokogiri
CVE-2023-29498Shared CWE-611
CVE-2024-52596Shared CWE-611
CVE-2023-40503Shared CWE-611
CVE-2023-29443Shared CWE-611

Affected Assets

nokogiri
nokogiri
≤ 1.19.4

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)
  • 2 hardening rules · 1 OS baseline
Validate
Prove the fix (OWASP ASVS)
  • V3.5.2
  • V4.4.2
  • V16.2.5
  • V1.5.1

Mitigating Controls (NIST 800-53 r5) AI

CM-6 Configuration Settings good match

Secure configuration settings can disable external entity processing in XML parsers.

SA-11 Developer Testing and Evaluation good match

Developer testing can discover XXE flaws through targeted XML parsing tests.

SI-10 Information Input Validation good match

SI-10 requires validity checks on inputs, which structurally replaces incomplete deny-lists with complete allow-list or sanitization logic.

AC-24 Access Control Decisions partial match

Applying access control decisions to each request depends on accurate property determination that accounts for case differences.

AC-3 Access Enforcement partial match

Correct enforcement of authorizations for resource access structurally requires consistent case-sensitive handling of identifiers to avoid incorrect decisions.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-01 mostly match
prevents

Hardened XML parser configurations directly disable external entity resolution.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly require complete, positive input validation instead of incomplete denylists.

ID.RA-01 partial match
prevents

Vulnerability scanning can discover XXE flaws but does not prevent their introduction in code.

PR.PS-02 partial match
prevents

Patching eliminates XXE-vulnerable parser versions but is only one aspect of software maintenance.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing can discover missing input checks, but does not prevent the weakness during development.

A.8.8 Management of technical vulnerabilities mostly match
finds

Vulnerability management identifies and patches XML libraries with unsafe default entity settings.

A.8.25 Secure development life cycle partial match
prevents

Secure SDLC practices should include case-sensitivity requirements in design and coding standards.

A.8.26 Application security requirements partial match
prevents

Application security requirements must specify case handling for identifiers and paths.

A.8.27 Secure system architecture and engineering principles partial match
prevents

Architecture principles should enforce canonical, case-aware resource naming.

A.8.28 Secure coding partial match
prevents

Secure coding guidelines must mandate explicit case handling to prevent inconsistent lookups.

References