{"schema":"threatline.record/2","record":{"id":"CVE-2026-104852","aliases":["GHSA-7mx3-vvmw-hjmv"],"summary":"GraphQL Tools has prototype pollution in well-established utility function `mergeDeep`","details":"Closed by https://github.com/ardatan/graphql-tools/pull/8423\nMitigated in Hive Gateway by https://github.com/graphql-hive/gateway/pull/2600\n\nA client can alias fields to `constructor`, `__proto__` or `prototype` so that the response keys from two subgraphs collide on those names during result merging. Because `mergeDeep` recursed through inherited properties, the merge walked `{}.constructor` to `Object`, then `Object.__proto__` to `Function.prototype`, and wrote a subgraph-supplied value over `Function.prototype.call`, breaking every subsequent request in the process until restart. This is remotely triggerable by an unauthenticated client with a single query against any supergraph that merges an object from two subgraphs, which is the ordinary `@shareable` or entity case, so it is a denial of service rather than a theoretical hardening issue.\n\n\n```graphql\n{\n  shared {\n    fieldA\n    constructor: fieldB {\n      __proto__: child {\n        call: value\n      }\n    }\n  }\n}\n```","categories":["Libraries & packages"],"product":"@graphql-tools/utils","vendor":"ardatan","ecosystem":"npm","affected_ranges":[{"source":"GitHub Advisory Database","source_url":"https://github.com/advisories/GHSA-7mx3-vvmw-hjmv","source_modified_at":"2026-10-05T22:56:48Z","fetched_at":"2026-10-23T18:42:43.628194Z","package":{"ecosystem":"npm","name":"@graphql-tools/utils"},"range":"<= 12.0.0"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-104852","source_modified_at":"2026-10-06T14:48:02.114Z","fetched_at":"2026-10-23T18:45:31.882637Z","product":"graphql-tools","vendor":"ardatan","versions":[{"version":"< 12.0.1","status":"affected"}],"defaultStatus":null},{"source":"OSV","source_url":"https://osv.dev/vulnerability/GHSA-7mx3-vvmw-hjmv","source_modified_at":"2026-10-05T23:15:03.990636467Z","fetched_at":"2026-10-23T18:42:43.628194Z","package":{"ecosystem":"npm","name":"@graphql-tools/utils","purl":"pkg:npm/%40graphql-tools/utils"},"ranges":[{"events":[{"introduced":"0"},{"fixed":"12.0.1"}],"type":"SEMVER"}],"versions":[]}],"fixed_versions":[{"source":"GitHub Advisory Database","source_url":"https://github.com/advisories/GHSA-7mx3-vvmw-hjmv","source_modified_at":"2026-10-05T22:56:48Z","fetched_at":"2026-10-23T18:42:43.628194Z","package":{"ecosystem":"npm","name":"@graphql-tools/utils"},"version":"12.0.1"},{"source":"OSV","source_url":"https://osv.dev/vulnerability/GHSA-7mx3-vvmw-hjmv","source_modified_at":"2026-10-05T23:15:03.990636467Z","fetched_at":"2026-10-23T18:42:43.628194Z","package":{"ecosystem":"npm","name":"@graphql-tools/utils","purl":"pkg:npm/%40graphql-tools/utils"},"version":"12.0.1"}],"cvss":8.2,"severity":"High","kev":{"listed":false},"epss":{"probability":0.00356,"percentile":0.28121,"score_date":"2026-10-23"},"published_at":"2026-10-05T22:56:43.779Z","modified_at":"2026-10-06T14:48:02.114Z","provenance":[{"source":"GitHub Advisory Database","url":"https://github.com/advisories/GHSA-7mx3-vvmw-hjmv","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-05T22:56:48Z"},{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-104852","fetched_at":"2026-10-23T18:45:31.882637Z","source_modified_at":"2026-10-06T14:48:02.114Z"},{"source":"OSV","url":"https://osv.dev/vulnerability/GHSA-7mx3-vvmw-hjmv","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-05T23:15:03.990636467Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-104852","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23"}],"sources":["GitHub Advisory Database","CVE List","OSV","EPSS"],"references":[{"source":"CVE List","url":"https://github.com/ardatan/graphql-tools/security/advisories/GHSA-7mx3-vvmw-hjmv","tags":["x_refsource_CONFIRM"]},{"source":"CVE List","url":"https://github.com/ardatan/graphql-tools/pull/8423","tags":["x_refsource_MISC"]},{"source":"CVE List","url":"https://github.com/graphql-hive/gateway/pull/2600","tags":["x_refsource_MISC"]},{"source":"CVE List","url":"https://github.com/ardatan/graphql-tools/commit/0b9529f1988fd36186a7c106a6efe0356f1b7f2e","tags":["x_refsource_MISC"]},{"source":"CVE List","url":"https://github.com/ardatan/graphql-tools/releases/tag/@graphql-tools/utils@12.0.1","tags":["x_refsource_MISC"]},{"url":"https://github.com/advisories/GHSA-7mx3-vvmw-hjmv","source":"GitHub Advisory Database"}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","ssvc":{"exploitation":"none","automatable":"no","technical_impact":"partial","assessed_at":"2026-10-06T14:34:12.166588Z"},"classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":"ecosystem","confidence":"heuristic","reviewed":false},"change_timestamp":"2026-10-06T14:48:02.114Z","content_hash":"977a15a7983d0e3b656427a7331669b055cb93382393a93007e577d00dade588"}}