CVE-2021-47996

Analyzed Analyzed - Analysis Complete

Memory Leak and Buffer Overflow in Nokogiri

Publication date: 2026-08-25

Last updated on: 2026-09-08

Assigner: VulnCheck

Description

Rejected reason: This CVE ID has been rejected as a duplicate.

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published

2026-08-25

Last Modified

2026-09-08

Generated

2026-09-14

AI Q&A

2026-08-25

EPSS Evaluated

2026-09-07

NVD

CVE-2021-47996

EUVD

EUVD-2021-34866

Affected Vendors & Products

Vendor	Product	Version / Range
nokogiri	nokogiri	to 1.11.4 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-119	The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.

Attack-Flow Graph

Executive Summary

CVE-2021-47996 affects Nokogiri versions before 1.11.4 when using its bundled libxml2 library. It involves multiple vulnerabilities in libxml2 2.9.10, including memory leaks, buffer overflows, and out-of-bounds reads. These flaws can cause denial of service, information disclosure, or memory corruption when processing crafted XML documents.

Detection Guidance

Check Nokogiri version with gem list nokogiri. If using packaged libxml2, verify version with xml2-config --version. Systems using libxml2 2.9.10 or earlier are vulnerable.

Impact Analysis

This vulnerability may allow attackers to crash applications, leak sensitive data, or execute arbitrary code by exploiting flaws in XML processing. Systems using vulnerable Nokogiri versions with bundled libxml2 are at risk if they process untrusted XML input.

Compliance Impact

This vulnerability primarily affects systems using Nokogiri with bundled libxml2 versions before 1.11.4. While it may lead to denial of service, information disclosure, or memory corruption, the provided text does not specify direct impacts on GDPR or HIPAA compliance. Compliance risks would depend on how the affected XML processing is used in systems handling regulated data.

Mitigation Strategies

Upgrade Nokogiri to version 1.11.4 or later using gem install nokogiri -v 1.11.4. If using system libxml2, update via your OS package manager.

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