CVE-2026-104852: GraphQL Tools has prototype pollution in well-established utility function `mergeDeep`
Vulnerability summary
CVE-2026-104852 is a high (CVSS 8.2) vulnerability in ardatan graphql-tools. EPSS estimates a 0.45% chance of exploitation in the next 30 days, higher than 39.2% of scored vulnerabilities.
Severe, CVSS 8.2 (CVE.org); no exploitation reported by the 5 checked sources; EPSS 0% (FIRST, 03-11-2026)
Source freshness unavailable
How is this decided?Timeline
- 05-10-2026PublishedVulnerability first disclosed.
- 06-10-2026Last modifiedVulnerability information updated.
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 metrics
5 scores · 5 sources · 1 version- OSV · NpmEcosystem advisory · calculated8.2HighCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
- OSV · ChainguardEcosystem advisory · calculated8.2HighCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
- NVDNIST8.2HighCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- OSV · WolfiEcosystem advisory · calculated8.2HighCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
EPSS trend
Probability
0.45%
Chance of exploitation in the next 30 days
Percentile
39%
Versus all other CVEs
30-day change
Change unavailable
Change unavailable
Known exploited
Compare KEV catalogsNot in the CISA KEV catalog.
Not in the ENISA CNW catalog.
Not in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.
Chainguard29 products
- commercial-gitlab-rails-ee-19.1< 19.1.7-r3
- commercial-gitlab-rails-ee-19.2< 19.2.7-r1
- commercial-gitlab-rails-ee-19.3< 19.3.3-r1
- commercial-gitlab-rails-ee-19.4< 19.4.1-r1
- commercial-gitlab-rails-ee-fips-19.1All versions (No fix recorded) | < 19.1.9-r0
@graphql-tools1 product
- utils< 12.0.1
Ardatan1 product
- graphql-tools< 12.0.1
Wolfi1 product
- langfuse-3-workerAll versions (No fix recorded) | < 3.225.11-r9
4 vendors · 32 products
References
8 links- github.com/ardatan/graphql-tools/security/advisories/GHSA-7mx3-vvmw-hjmvX Refsource CONFIRMWEBAdvisory
- github.com/ardatan/graphql-tools/commit/0b9529f1988fd36186a7c106a6efe0356f1b7f2eX Refsource MISCWEBFIX