Answer in brief
CVE-2021-23383 records a Medium severity (CVSS 5.6) vulnerability in Prototype Pollution. The current sources do not mark it as known exploited. The current feed maps n/a/handlebars (generic), handlebars (npm). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 5.6. 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 n/a/handlebars (generic), handlebars (npm). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| n/a/handlebarsgeneric | >=unspecified <4.7.7 | 4.7.7 |
| handlebarsnpm | >=0 <4.7.7 | 4.7.7 |
Published upstream
May 4, 2021
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 8, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 7, 2026
The package handlebars before 4.7.7 are vulnerable to Prototype Pollution when selecting certain compiling options to compile templates coming from an untrusted source.
Quoted source text, attributed separately from HOL analysis.