Answer in brief
CVE-2021-47996 records a Unknown severity vulnerability in Nokogiri before 1.11.4 Multiple Vulnerabilities via libxml2. The current sources do not mark it as known exploited. The current feed maps sparklemotion/nokogiri (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps sparklemotion/nokogiri (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| sparklemotion/nokogirigeneric | >=0 <1.11.4 | 1.11.4 |
Published upstream
Aug 25, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 25, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 25, 2026
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.
Quoted source text, attributed separately from HOL analysis.