Answer in brief
CVE-2026-104852 records a High severity (CVSS 8.2) vulnerability in GraphQL Tools has prototype pollution in well-established utility function `mergeDeep`. The current sources do not mark it as known exploited. The current feed maps ardatan/graphql-tools (generic), @graphql-tools/utils (npm), @graphql-tools/utils (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 8.2. 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 ardatan/graphql-tools (generic), @graphql-tools/utils (npm), @graphql-tools/utils (npm). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| ardatan/graphql-toolsgeneric | <12.0.1 | 12.0.1 |
| @graphql-tools/utilsnpm | <=12.0.0 | 12.0.1 |
| @graphql-tools/utilsnpm | >=0 <12.0.1 | 12.0.1 |
Published upstream
Oct 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Oct 5, 2026
GraphQL Tools provides utilities for building, stitching, and mocking GraphQL schemas. Prior to 12.0.1, the GraphQL Tools utils package's mergeDeep function follows inherited properties while recursively merging source objects and does not exclude __proto__, constructor, or prototype keys. An unauthenticated GraphQL client can alias fields to those names so responses from two subgraphs collide during ordinary supergraph result merging, causing mergeDeep to traverse Object and Function prototypes and overwrite Function.prototype.call with a subgraph-supplied value. This breaks subsequent requests in the process until restart. This issue is fixed in version 12.0.1.
Quoted source text, attributed separately from HOL analysis.