CVE-2021-47996

high

Description

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.

References

https://www.vulncheck.com/advisories/nokogiri-before-multiple-vulnerabilities-via-libxml2

https://github.com/sparklemotion/nokogiri/security/advisories/GHSA-7rrm-v45f-jp64

https://github.com/GNOME/libxml2/commit/bf22713507fe1fc3a2c4b525cf0a88c2dc87a3a2

https://github.com/GNOME/libxml2/commit/babe75030c7f64a37826bb3342317134568bef61

https://github.com/GNOME/libxml2/commit/8598060bacada41a0eb09d95c97744ff4e428f8e

https://github.com/GNOME/libxml2/commit/7ffcd44d7e6c46704f8af0321d9314cd26e0e18a

https://github.com/GNOME/libxml2/commit/50f06b3efb638efb0abd95dc62dca05ae67882c2

https://github.com/GNOME/libxml2/commit/1358d157d0bd83be1dfe356a69213df9fac0b539

https://github.com/GNOME/libxml2/commit/1098c30a040e72a4654968547f415be4e4c40fe7

https://github.com/GNOME/libxml2/commit/0e1a49c8907645d2e155f0d89d4d9895ac5112b5

Details

Source: Mitre, NVD

Published: 2026-08-25

Updated: 2026-09-01

Risk Information

CVSS v2

Base Score: 7.8

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:C

Severity: High

CVSS v3

Base Score: 7.5

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Severity: High

CVSS v4

Base Score: 8.7

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Severity: High

EPSS

EPSS: 0.00515