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CVE-2026-57236

Nokogiri: Possible Use-After-Free when `Nokogiri::XML::Document#encoding=` raises an exception

Published: Jun 25, 2026Updated: Jun 26, 2026 Sources: CVE List NVDCWE-416
8.2HIGH
NVD MITRE
EPSS Score
0.3%
Top 73.3%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Workaround Only
Self-Check
Not available

Description

Nokogiri is an open source XML and HTML library for the Ruby programming language. Prior to 1.19.4, calling Document#encoding= with an invalid encoding (e.g., a non-string, or a string containing a null byte) raises an exception, but only after freeing the document's current encoding string without replacing it. The document is left referencing freed memory, so the next call to Document#encoding reads invalid memory, which can cause a segfault or leak freed bytes into a Ruby String. Affects the CRuby (libxml2) implementation only; JRuby is not affected. This vulnerability is fixed in 1.19.4.

No summary for this CVE yet.

CVSS Vector Breakdown

AV:NAC:LPR:NUI:NS:UC:LI:NA:H
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:NPrivileges Required
None
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:LConfidentiality
Low
I:NIntegrity
None
A:HAvailability
High
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Weaknesses

CWE-416

Affected Products

nokogiri
oss-project
nokogiriLibrary
OSS Libraries / generic-library
sparklemotion
oss-project
nokogiriLibrary
OSS Libraries / generic-library

Exploitability

Workaround Available
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Attack Graph

Products CVE Techniques Tactics

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MITRE ATT&CK

2 techniques
Initial Access
Privilege Escalation
View detailed technique mapping

References

https://github.com/sparklemotion/nokogiri/security/advisories/GHSA-5v8h-3h3q-446p
github.com

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