High severity · published Oct 1, 2026
CVE-2026-103921
GraphQL Tools: TLS Certificate Validation Disabled in Legacy GraphQL WebSocket Executor
7.4
CVSS
0.3%
EPSS
No
On KEV
Description
GraphQL Tools provides utilities for building, stitching, and mocking GraphQL schemas. Prior to 1.1.35, the executor-legacy-ws buildWSLegacyExecutor() function hardcodes TLS certificate rejection off for Node.js connections to wss:// endpoints. Applications using the executor directly, or url-loader with SubscriptionProtocol.LEGACY_WS, can therefore accept an attacker-controlled certificate when a network-positioned attacker intercepts the connection. Authentication material in connectionParams or headers can be disclosed, and subscription data can be modified. Browser WebSocket clients are unaffected because browsers enforce certificate validation. This issue is fixed in version 1.1.35.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
Attack vector
Network
Complexity
High
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 20% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
EX
executor-legacy-ws · @graphql-tools
< 1.1.35 · source: vendor
GR
graphql-tools · ardatan
< 1.1.35 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-103921
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-103921
x_refsource_CONFIRM
https://github.com/ardatan/graphql-tools/security/advisories/GHSA-6fw5-9hq8-w87g
x_refsource_MISC
https://github.com/ardatan/graphql-tools/pull/8426
x_refsource_MISC
https://github.com/ardatan/graphql-tools/commit/3831a0661514c91d99971052f983552556880402
x_refsource_MISC
https://github.com/ardatan/graphql-tools/releases/tag/@graphql-tools/executor-legacy-ws@1.1.35
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