High7.5Red Hat Linux

High [CVE-2021-47996] Memory Corruption via Crafted XML Documents

This high-severity Red Hat Linux advisory covers CVE-2021-47996 affecting Red Hat 3scale API Management Platform 2, Red Hat Satellite 6.

CVE-2021-47996 Published Aug 25, 2026Updated by vendor Aug 25, 2026

CVE-2021-47996

Affected products & platforms

Red Hat LinuxUnclassified

Open vendor advisory

Android app · Google Play

Monitor future Red Hat Linux CVEs from your phone.

Choose a whole vendor or a precise platform, then receive matching security advisories by phone notification, email, or both. Coverage follows 32 official vendor sources and 160+ reviewed platform categories.

Matching phone alertsOptional email delivery

Get CVE alerts See app features

Summary

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. 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. Red Hat severity: Important — CVSS 7.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).

Weakness: CWE-125. Affected Red Hat products: Red Hat 3scale API Management Platform 2; Red Hat Satellite 6.

Red Hat does not currently list a fixing RHSA for this CVE.

Affected versions

< 1.11.4
< 2.9.10
< 2.9.12

Official advisory · high-confidence parse· fetched 45 minutes ago·verify at source

Fixed versions

No fixed release is recorded yet. That does not prove no patch exists — confirm against the vendor advisory.

Official advisory · high-confidence parse· fetched 45 minutes ago·verify at source

Mitigation

The source record does not include mitigation steps. That is not a statement that no fix exists — read the vendor advisory below for the authoritative guidance.

Official advisory · high-confidence parse· fetched 45 minutes ago·verify at source

Discussion(0)

No comments yet. Share field notes, upgrade gotchas, or questions — verify against the vendor advisory before acting on community advice.