CVE-2026-104852
GraphQL Tools has prototype pollution in well-established utility function `mergeDeep`
Reported by github_m · Published October 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.
Fixed versions
Upgrade to a fixed version or later. Language registries are listed first, then Linux distributions, then vendor products.
| Package | Ecosystem | Fixed in |
|---|---|---|
| gitlab-rails-ce-fips-19.4 | Chainguard | 19.4.1-r8 |
| commercial-gitlab-rails-ee-19.3 | Chainguard | 19.3.3-r1 |
| gitlab-rails-ce-fips-19.1 | Chainguard | 19.1.8-r9 |
| gitlab-rails-ce-fips-19.2 | Chainguard | 19.2.8-r1 |
| commercial-gitlab-rails-ee-fips-19.1 | Chainguard | 19.1.9-r0 |
| gitlab-rails-ce-fips-18.11 | Chainguard | 18.11.12-r2 |
| commercial-gitlab-rails-ee-fips-19.4 | Chainguard | 19.4.1-r1 |
| commercial-gitlab-rails-ee-19.4 | Chainguard | 19.4.1-r1 |
| commercial-gitlab-rails-ee-fips-19.2 | Chainguard | 19.2.7-r1 |
| gitlab-rails-ce-fips-18.10 | Chainguard | 18.10.8-r8 |
| gitlab-rails-ce-fips-19.0 | Chainguard | 19.0.9-r3 |
| gitlab-rails-ce-19.4 | Chainguard | 19.4.2-r4 |
Risk scores
Affected products
| Vendor | Product | Versions |
|---|---|---|
| ardatan | graphql-tools | < 12.0.1 |
| chainguard | gitlab-rails-ce-fips-19.4 | 0 |
| chainguard | commercial-gitlab-rails-ee-19.3 | 0 |
| chainguard | gitlab-rails-ce-fips-19.1 | 0 |
| chainguard | gitlab-rails-ce-fips-19.2 | 0 |
| chainguard | commercial-gitlab-rails-ee-fips-19.1 | 0 |
| chainguard | gitlab-rails-ce-fips-18.11 | 0 |
| chainguard | commercial-gitlab-rails-ee-fips-19.4 | 0 |
| chainguard | commercial-gitlab-rails-ee-19.4 | 0 |
| chainguard | commercial-gitlab-rails-ee-fips-19.2 | 0 |
| chainguard | gitlab-rails-ce-fips-18.10 | 0 |
| chainguard | gitlab-rails-ce-fips-19.0 | 0 |
| chainguard | gitlab-rails-ce-19.4 | 0 |
| ardatan | graphql-tools | 0 |
| wolfi | langfuse-3 | 0 |
| chainguard | langfuse-fips-3 | 0 |
| graphql-tools | utils | 0 |
| chainguard | commercial-gitlab-rails-ee-fips-19.3 | 0 |
| chainguard | langfuse-3 | 0 |
| chainguard | gitlab-rails-ce-fips-18.9 | 0 |
…and 5 more
Timeline
- Oct 5, 2026 CVE Published
- Oct 6, 2026 EPSS Score (12 in total, the first dated here)
- Oct 6, 2026 Coalition ESS Score
- Oct 6, 2026 CVE Updated
- Oct 30, 2026 Security Advisory
Query this with the API
The same record, from the CLI:
vulnetix vdb vuln CVE-2026-104852
vulnetix vdb fixes CVE-2026-104852Or with curl, using the org id and key from your account page:
curl -s -H "Authorization: ApiKey ${VULNETIX_ORG_ID}:${VULNETIX_API_KEY}" \
"https://api.vdb.vulnetix.com/v2/vuln/CVE-2026-104852/fixes/registry"The Community plan is free and allows 50 queries a day. Get a free API key · API quickstart
References
- https://github.com/ardatan/graphql-tools/security/advisories/GHSA-7mx3-vvmw-hjmv x_refsource_CONFIRM
- https://github.com/ardatan/graphql-tools/pull/8423 x_refsource_MISC
- https://github.com/graphql-hive/gateway/pull/2600 x_refsource_MISC
- https://github.com/ardatan/graphql-tools/commit/0b9529f1988fd36186a7c106a6efe0356f1b7f2e x_refsource_MISC
- https://github.com/ardatan/graphql-tools/releases/tag/@graphql-tools/utils@12.0.1 x_refsource_MISC
- https://nvd.nist.gov/vuln/detail/CVE-2026-104852 advisory
- https://github.com/advisories/GHSA-7mx3-vvmw-hjmv advisory