🛡️ CVE-2026-57235 — nokogiri

🟠 CVSS 8.2 — High ✅ No Known Exploit CWE-125 OSV
8.2
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

Nokogiri: Possible Out-of-Bounds Read in Nokogiri::XML::NodeSet#[]

Summary

Nokogiri::XML::NodeSet#[] (and its alias #slice) checked the requested index against the node set's bounds using a 32-bit-truncated copy of the index. A large negative index could pass the check and then be used at full width, reading outside the node set's storage. On CRuby this is an out-of-bounds read that typically crashes the process; on JRuby it is not memory-unsafe but returns an incorrect node.

Nokogiri 1.19.4 performs the bounds check against the full-width index.

Severity

The Nokogiri maintainers have evaluated this as medium severity.

Exploitation requires an application to pass an attacker-controlled integer to NodeSet#[]. The primary impact is a controlled crash (denial of service), with potential for memory disclosure on CRuby.

On JRuby, Nokogiri is not affected by this vulnerability.

Mitigation

Upgrade to Nokogiri 1.19.4 or later.

As a workaround, applications that index a NodeSet with externally-supplied integers can validate the index against node_set.length before use, or avoid passing untrusted values as an index.

Credit

This issue was responsibly reported by Zheng Yu from depthfirst.com.

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is low, an attacker needs no privileges on the target. No user interaction is required. Rated impact: confidentiality low, integrity none, availability low.

Weakness class

CVE-2026-57235 is classified as CWE-125: Out-of-bounds Read. The code reads past the limits of a buffer, exposing adjacent memory contents or crashing the process.

Affected software

CVE-2026-57235 is recorded against 1 package.

  • nokogiri (fixed in 1.19.4)

Timeline and source

Published on 19 June 2026 and last revised on 8 July 2026. No public exploit is currently recorded for this entry. Record sourced from OSV.

References

github.com (Web)
github.com (Package)

Details

Severity HIGH
CVSS Score 8.2
CVSS Vector CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N
CWE CWE-125
Public Exploit ✅ No
Source OSV
Published 2026-06-19
Updated 2026-08-12
Modified 2026-07-08
Fix URL N/A

Affected Packages

Software From version Fixed in
nokogiri — 1.19.4

Similar Threats

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