{"cve":"CVE-2026-104852","nvd":{"published":"2026-10-05T23:17:00.213","modified":"2026-10-06T15:17:13.110","status":"Awaiting Analysis","description":"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.","cvss_v4":{"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","score":8.2},"cvss_v3":null,"cwes":["CWE-1321"],"references":["https://github.com/ardatan/graphql-tools/commit/0b9529f1988fd36186a7c106a6efe0356f1b7f2e","https://github.com/ardatan/graphql-tools/pull/8423","https://github.com/ardatan/graphql-tools/releases/tag/@graphql-tools/utils@12.0.1","https://github.com/ardatan/graphql-tools/security/advisories/GHSA-7mx3-vvmw-hjmv","https://github.com/graphql-hive/gateway/pull/2600"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:57:46.668721662+00:00"},"epss":{"cve":"CVE-2026-104852","score":0.00356,"percentile":0.29021,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-7mx3-vvmw-hjmv","url":"https://osv.dev/vulnerability/GHSA-7mx3-vvmw-hjmv","summary":"GraphQL Tools has prototype pollution in well-established utility function `mergeDeep`","modified":"2026-10-05T23:15:03.990636467Z","packages":[{"ecosystem":"npm","name":"@graphql-tools/utils","purl":"pkg:npm/%40graphql-tools/utils","ranges":["<12.0.1"],"fixed":["12.0.1"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}