Bug 2546183 (CVE-2026-104852)

Summary:	CVE-2026-104852 @graphql-tools/utils: @graphql-tools/utils: Denial of Service (DoS) via prototype pollution in mergeDeep
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	high	Docs Contact:
Priority:	high
Version:	unspecified	CC:	abarbaro, akhatavk, alizardo, aos-team-art-private, asdas, dpaolell, dschmidt, ikhan, jchui, jdelft, jhe, jlanda, jupierce, kshier, ktsao, lgarciaa, mbiarnes, nboldt, oaljalju, ppalepu, ppostler, prdhamdh, psrna, rbobbitt, sghai, sidsharm, simaishi, stcannon, suppawar, vlaad, yguenane
Target Milestone:	---	Keywords:	Security
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Hardware:	All
OS:	Linux
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Doc Text:	A flaw was found in @graphql-tools/utils. The mergeDeep function fails to restrict sensitive object properties during recursive data merging, leading to prototype pollution, where fundamental JavaScript object definitions are modified. A remote, unauthenticated attacker can exploit this flaw by sending a crafted GraphQL query with aliased field names to trigger a collision during response merging. Successful exploitation overwrites internal runtime methods, resulting in a Denial of Service (DoS) that prevents the application from handling subsequent requests until restarted.	Story Points:	---
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-10-05 23:01:25 UTC

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.