Bug 2523549 (CVE-2021-47996)

Summary:	CVE-2021-47996 nokogiri: libxml2: Nokogiri: Memory Corruption via Crafted XML Documents
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	high	Docs Contact:
Priority:	high
Version:	unspecified	CC:	akostadi, amasferr, anthomas, crizzo, dmayorov, ehelms, eshamard, ggainey, jlledo, jpasqual, juwatts, jvasik, kaycoth, mdellweg, mhulan, nmoumoul, osousa, pantinor, pcreech, rblanco, rchan, rhel-process-autobot, smallamp, tmalecek, tsedmik, watson-tool-maintainers
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
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Doc Text:	A flaw was found in Nokogiri, specifically within its bundled libxml2 library. A remote attacker could exploit multiple vulnerabilities, including memory leaks, buffer over-reads, heap-based buffer overflows, and out-of-bounds reads, by processing specially crafted XML documents. This could lead to memory corruption, information disclosure, or a denial of service.	Story Points:	---
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-08-25 15:32:32 UTC

Nokogiri before 1.11.4 (CRuby implementation only, when the packaged/vendored libxml2 is used) bundles libxml2 2.9.10, which is affected by multiple vulnerabilities addressed in libxml2 2.9.12, including a memory leak in xmlSchemaValidateStream (CVE-2019-20388), a global buffer over-read in xmlEncodeEntitiesInternal (CVE-2020-24977), a heap-based buffer overflow (CVE-2021-3517), and an out-of-bounds read (CVE-2021-3518). Processing crafted XML documents may lead to denial of service, information disclosure, or memory corruption.