Withdrawn: this CVE is not a vulnerability
The assigning CNA withdrew CVE-2021-47996 on 8 September 2026, and it carries the Rejected state at CVE.org and NVD. It must not be treated as a live finding. Its pre-withdrawal severity, score and exploitability are withheld below; the record itself is kept because withdrawals are reversible and because the reject reason is the correction worth publishing.
WITHDRAWN
CVE-2021-47996
Nokogiri before 1.11.4 Multiple Vulnerabilities via libxml2
Overview
Description
Rejected reason: This CVE ID has been rejected as a duplicate.
Details
INFO
Published Date :
Aug. 25, 2026, 4:16 p.m.
Last Modified :
Sept. 8, 2026, 3:17 p.m.
Remotely Exploit :
—
Source :
[email protected]
Scoring
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework
for assessing the severity of vulnerabilities in software and systems.
We collect and displays CVSS scores from various sources for each CVE.
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | HIGH | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 3.1 | HIGH | [email protected] | ||||
| CVSS 3.1 | HIGH | MITRE-CVE | ||||
| CVSS 4.0 | HIGH | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 4.0 | HIGH | [email protected] |
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.
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CVE Rejected by [email protected]
Sep. 08, 2026
Action Type Old Value New Value -
CVE Modified by [email protected]
Sep. 08, 2026
Action Type Old Value New Value Changed 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. Rejected reason: This CVE ID has been rejected as a duplicate. Removed CVSS V4.0 VulnCheck: 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 Removed CVSS V3.1 VulnCheck: AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Removed CVSS V3.1 nvd-ai-agent-0.3.0-gemma-4-31B-it: AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H Removed CWE VulnCheck: CWE-119 Removed CWE nvd-ai-agent-0.3.0-gemma-4-31B-it: CWE-125 Removed CPE Configuration OR *cpe:2.3:a:nokogiri:nokogiri:*:*:*:*:*:ruby:*:* versions up to (excluding) 1.11.4 Removed CPE Configuration OR *cpe:2.3:a:nokogiri:nokogiri:*:*:*:*:*:*:*:* versions up to (excluding) 1.11.4 Added Affected Affected value removed. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2021/47xxx/CVE-2021-47996.json">CVE-2021-47996</a> Removed Reference VulnCheck: https://github.com/GNOME/libxml2/commit/0e1a49c8907645d2e155f0d89d4d9895ac5112b5 Removed Reference VulnCheck: https://github.com/GNOME/libxml2/commit/1098c30a040e72a4654968547f415be4e4c40fe7 Removed Reference VulnCheck: https://github.com/GNOME/libxml2/commit/1358d157d0bd83be1dfe356a69213df9fac0b539 Removed Reference VulnCheck: https://github.com/GNOME/libxml2/commit/50f06b3efb638efb0abd95dc62dca05ae67882c2 Removed Reference VulnCheck: https://github.com/GNOME/libxml2/commit/7ffcd44d7e6c46704f8af0321d9314cd26e0e18a Removed Reference VulnCheck: https://github.com/GNOME/libxml2/commit/8598060bacada41a0eb09d95c97744ff4e428f8e Removed Reference VulnCheck: https://github.com/GNOME/libxml2/commit/babe75030c7f64a37826bb3342317134568bef61 Removed Reference VulnCheck: https://github.com/GNOME/libxml2/commit/bf22713507fe1fc3a2c4b525cf0a88c2dc87a3a2 Removed Reference VulnCheck: https://github.com/sparklemotion/nokogiri/security/advisories/GHSA-7rrm-v45f-jp64 Removed Reference VulnCheck: https://www.vulncheck.com/advisories/nokogiri-before-multiple-vulnerabilities-via-libxml2 Removed Reference nvd-ai-agent-0.3.0-gemma-4-31B-it: https://github.com/sparklemotion/nokogiri/commit/0e1a49c8907645d2e155f0d89d4d9895ac5112b5 Removed Reference nvd-ai-agent-0.3.0-gemma-4-31B-it: https://github.com/sparklemotion/nokogiri/commit/1098c30a040e72a4654968547f415be4e4c40fe7 Removed Reference nvd-ai-agent-0.3.0-gemma-4-31B-it: https://github.com/sparklemotion/nokogiri/commit/1358d157d0bd83be1dfe356a69213df9fac0b539 Removed Reference nvd-ai-agent-0.3.0-gemma-4-31B-it: https://github.com/sparklemotion/nokogiri/commit/50f06b3efb638efb0abd95dc62dca05ae67882c2 Removed Reference nvd-ai-agent-0.3.0-gemma-4-31B-it: https://github.com/sparklemotion/nokogiri/commit/7ffcd44d7e6c46704f8af0321d9314cd26e0e18a Removed Reference nvd-ai-agent-0.3.0-gemma-4-31B-it: https://github.com/sparklemotion/nokogiri/commit/8598060bacada41a0eb09d95c97744ff4e428f8e Removed Reference nvd-ai-agent-0.3.0-gemma-4-31B-it: https://github.com/sparklemotion/nokogiri/commit/babe75030c7f64a37826bb3342317134568bef61 Removed Reference nvd-ai-agent-0.3.0-gemma-4-31B-it: https://github.com/sparklemotion/nokogiri/commit/bf22713507fe1fc3a2c4b525cf0a88c2dc87a3a2 Removed Reference nvd-ai-agent-0.3.0-gemma-4-31B-it: https://github.com/sparklemotion/nokogiri/security/advisories/GHSA-7rrm-v45f-jp64 Removed Reference nvd-ai-agent-0.3.0-gemma-4-31B-it: https://www.vulncheck.com/advisories/nokogiri-before-multiple-vulnerabilities-via-libxml2 Removed Reference Type VulnCheck: https://github.com/GNOME/libxml2/commit/0e1a49c8907645d2e155f0d89d4d9895ac5112b5 Types: Patch Removed Reference Type VulnCheck: https://github.com/GNOME/libxml2/commit/1098c30a040e72a4654968547f415be4e4c40fe7 Types: Patch Removed Reference Type VulnCheck: https://github.com/GNOME/libxml2/commit/1358d157d0bd83be1dfe356a69213df9fac0b539 Types: Patch Removed Reference Type VulnCheck: https://github.com/GNOME/libxml2/commit/50f06b3efb638efb0abd95dc62dca05ae67882c2 Types: Patch Removed Reference Type VulnCheck: https://github.com/GNOME/libxml2/commit/7ffcd44d7e6c46704f8af0321d9314cd26e0e18a Types: Patch Removed Reference Type VulnCheck: https://github.com/GNOME/libxml2/commit/8598060bacada41a0eb09d95c97744ff4e428f8e Types: Patch Removed Reference Type VulnCheck: https://github.com/GNOME/libxml2/commit/babe75030c7f64a37826bb3342317134568bef61 Types: Patch Removed Reference Type VulnCheck: https://github.com/GNOME/libxml2/commit/bf22713507fe1fc3a2c4b525cf0a88c2dc87a3a2 Types: Patch Removed Reference Type VulnCheck: https://github.com/sparklemotion/nokogiri/security/advisories/GHSA-7rrm-v45f-jp64 Types: Vendor Advisory Removed Reference Type VulnCheck: https://www.vulncheck.com/advisories/nokogiri-before-multiple-vulnerabilities-via-libxml2 Types: Third Party Advisory Removed Reference Type nvd-ai-agent-0.3.0-gemma-4-31B-it: https://github.com/sparklemotion/nokogiri/commit/0e1a49c8907645d2e155f0d89d4d9895ac5112b5 Types: Broken Link Removed Reference Type nvd-ai-agent-0.3.0-gemma-4-31B-it: https://github.com/sparklemotion/nokogiri/commit/1098c30a040e72a4654968547f415be4e4c40fe7 Types: Broken Link Removed Reference Type nvd-ai-agent-0.3.0-gemma-4-31B-it: https://github.com/sparklemotion/nokogiri/commit/1358d157d0bd83be1dfe356a69213df9fac0b539 Types: Broken Link Removed Reference Type nvd-ai-agent-0.3.0-gemma-4-31B-it: https://github.com/sparklemotion/nokogiri/commit/50f06b3efb638efb0abd95dc62dca05ae67882c2 Types: Broken Link Removed Reference Type nvd-ai-agent-0.3.0-gemma-4-31B-it: https://github.com/sparklemotion/nokogiri/commit/7ffcd44d7e6c46704f8af0321d9314cd26e0e18a Types: Broken Link Removed Reference Type nvd-ai-agent-0.3.0-gemma-4-31B-it: https://github.com/sparklemotion/nokogiri/commit/8598060bacada41a0eb09d95c97744ff4e428f8e Types: Broken Link Removed Reference Type nvd-ai-agent-0.3.0-gemma-4-31B-it: https://github.com/sparklemotion/nokogiri/commit/babe75030c7f64a37826bb3342317134568bef61 Types: Broken Link Removed Reference Type nvd-ai-agent-0.3.0-gemma-4-31B-it: https://github.com/sparklemotion/nokogiri/commit/bf22713507fe1fc3a2c4b525cf0a88c2dc87a3a2 Types: Broken Link Removed Reference Type nvd-ai-agent-0.3.0-gemma-4-31B-it: https://github.com/sparklemotion/nokogiri/security/advisories/GHSA-7rrm-v45f-jp64 Types: Patch, Vendor Advisory Removed Reference Type nvd-ai-agent-0.3.0-gemma-4-31B-it: https://www.vulncheck.com/advisories/nokogiri-before-multiple-vulnerabilities-via-libxml2 Types: Broken Link -
Initial Analysis by [email protected]
Sep. 01, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:nokogiri:nokogiri:*:*:*:*:*:ruby:*:* versions up to (excluding) 1.11.4 Added Reference Type VulnCheck: https://github.com/GNOME/libxml2/commit/0e1a49c8907645d2e155f0d89d4d9895ac5112b5 Types: Patch Added Reference Type VulnCheck: https://github.com/GNOME/libxml2/commit/1098c30a040e72a4654968547f415be4e4c40fe7 Types: Patch Added Reference Type VulnCheck: https://github.com/GNOME/libxml2/commit/1358d157d0bd83be1dfe356a69213df9fac0b539 Types: Patch Added Reference Type VulnCheck: https://github.com/GNOME/libxml2/commit/50f06b3efb638efb0abd95dc62dca05ae67882c2 Types: Patch Added Reference Type VulnCheck: https://github.com/GNOME/libxml2/commit/7ffcd44d7e6c46704f8af0321d9314cd26e0e18a Types: Patch Added Reference Type VulnCheck: https://github.com/GNOME/libxml2/commit/8598060bacada41a0eb09d95c97744ff4e428f8e Types: Patch Added Reference Type VulnCheck: https://github.com/GNOME/libxml2/commit/babe75030c7f64a37826bb3342317134568bef61 Types: Patch Added Reference Type VulnCheck: https://github.com/GNOME/libxml2/commit/bf22713507fe1fc3a2c4b525cf0a88c2dc87a3a2 Types: Patch Added Reference Type VulnCheck: https://github.com/sparklemotion/nokogiri/security/advisories/GHSA-7rrm-v45f-jp64 Types: Vendor Advisory Added Reference Type VulnCheck: https://www.vulncheck.com/advisories/nokogiri-before-multiple-vulnerabilities-via-libxml2 Types: Third Party Advisory -
CVE Modified by [email protected]
Aug. 28, 2026
Action Type Old Value New Value Added Reference https://github.com/GNOME/libxml2/commit/0e1a49c8907645d2e155f0d89d4d9895ac5112b5 Added Reference https://github.com/GNOME/libxml2/commit/1098c30a040e72a4654968547f415be4e4c40fe7 Added Reference https://github.com/GNOME/libxml2/commit/1358d157d0bd83be1dfe356a69213df9fac0b539 Added Reference https://github.com/GNOME/libxml2/commit/50f06b3efb638efb0abd95dc62dca05ae67882c2 Added Reference https://github.com/GNOME/libxml2/commit/7ffcd44d7e6c46704f8af0321d9314cd26e0e18a Added Reference https://github.com/GNOME/libxml2/commit/8598060bacada41a0eb09d95c97744ff4e428f8e Added Reference https://github.com/GNOME/libxml2/commit/babe75030c7f64a37826bb3342317134568bef61 Added Reference https://github.com/GNOME/libxml2/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 Removed Reference https://github.com/sparklemotion/nokogiri/commit/0e1a49c8907645d2e155f0d89d4d9895ac5112b5 Removed Reference https://github.com/sparklemotion/nokogiri/commit/1098c30a040e72a4654968547f415be4e4c40fe7 Removed Reference https://github.com/sparklemotion/nokogiri/commit/1358d157d0bd83be1dfe356a69213df9fac0b539 Removed Reference https://github.com/sparklemotion/nokogiri/commit/50f06b3efb638efb0abd95dc62dca05ae67882c2 Removed Reference https://github.com/sparklemotion/nokogiri/commit/7ffcd44d7e6c46704f8af0321d9314cd26e0e18a Removed Reference https://github.com/sparklemotion/nokogiri/commit/8598060bacada41a0eb09d95c97744ff4e428f8e Removed Reference https://github.com/sparklemotion/nokogiri/commit/babe75030c7f64a37826bb3342317134568bef61 Removed Reference https://github.com/sparklemotion/nokogiri/commit/bf22713507fe1fc3a2c4b525cf0a88c2dc87a3a2 Removed Reference https://github.com/sparklemotion/nokogiri/security/advisories/GHSA-7rrm-v45f-jp64 Removed Reference https://www.vulncheck.com/advisories/nokogiri-before-multiple-vulnerabilities-via-libxml2 -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Aug. 25, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2021-47996', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'yes'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-08-25T17:19:25.611074Z'} -
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
EPSS is a daily estimate of the probability of exploitation activity
being observed over the next 30 days. Following chart shows the EPSS
score history of the vulnerability.