CVE-2021-47996
Nokogiri before 1.11.4 Multiple Vulnerabilities via libxml2
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.
INFO
Published Date :
Aug. 25, 2026, 4:16 p.m.
Last Modified :
Aug. 25, 2026, 4:16 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2021-47996
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 3.1 | HIGH | [email protected] | ||||
| CVSS 4.0 | HIGH | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 4.0 | HIGH | [email protected] |
Solution
- Update Nokogiri to version 1.11.4 or later.
- Ensure libxml2 is updated to 2.9.12 or later.
- Recompile software if necessary.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2021-47996.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2021-47996 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2021-47996
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2021-47996 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2021-47996 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
Aug. 25, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'sparklemotion', 'product': 'nokogiri', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '1.11.4', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '1.11.4', 'versionType': 'semver'}], 'packageURL': 'pkg:gem/nokogiri', 'defaultStatus': 'unaffected'}] Added 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. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Added CWE CWE-119 Added Reference https://github.com/sparklemotion/nokogiri/commit/0e1a49c8907645d2e155f0d89d4d9895ac5112b5 Added Reference https://github.com/sparklemotion/nokogiri/commit/1098c30a040e72a4654968547f415be4e4c40fe7 Added Reference https://github.com/sparklemotion/nokogiri/commit/1358d157d0bd83be1dfe356a69213df9fac0b539 Added Reference https://github.com/sparklemotion/nokogiri/commit/50f06b3efb638efb0abd95dc62dca05ae67882c2 Added Reference https://github.com/sparklemotion/nokogiri/commit/7ffcd44d7e6c46704f8af0321d9314cd26e0e18a Added Reference https://github.com/sparklemotion/nokogiri/commit/8598060bacada41a0eb09d95c97744ff4e428f8e Added Reference https://github.com/sparklemotion/nokogiri/commit/babe75030c7f64a37826bb3342317134568bef61 Added Reference https://github.com/sparklemotion/nokogiri/commit/bf22713507fe1fc3a2c4b525cf0a88c2dc87a3a2 Added Reference https://github.com/sparklemotion/nokogiri/security/advisories/GHSA-7rrm-v45f-jp64 Added Reference https://www.vulncheck.com/advisories/nokogiri-before-multiple-vulnerabilities-via-libxml2