Advisories for Npm/@Graphql-Tools/Executor-Legacy-Ws package

2026

GraphQL Tools: Shared legacy executor routes one subscription's results to a different caller

buildWSLegacyExecutor keeps one WebSocket in closure state and installs the message handler by assigning to the socket's single websocket.onmessage property inside subscribe(). Every new subscription therefore overwrites the previous subscriber's handler, and the handler's case LEGACY_WS.DATA branch calls observer.next(data.payload) without ever comparing data.id to the operation id that this subscription created at line 103 and sent with START at line 123. When one executor instance is reused for overlapping subscriptions, …

GraphQL Tools: Per-request connection parameters persist into later users' WebSocket authentications

buildWSLegacyExecutor keeps a single closure-scoped object, executorConnectionParams, for the lifetime of the executor. Every execution that carries request.extensions.connectionParams merges those keys into that object with Object.assign, and the object is merged into the connection_init payload each time a new WebSocket opens. Nothing ever removes keys: cleanupWebsocket terminates the socket and nulls the handle but leaves executorConnectionParams intact, and a later request that simply omits a key skips the conditional update …

GraphQL Tools: TLS Certificate Validation Disabled in Legacy GraphQL WebSocket Executor

buildWSLegacyExecutor() in @graphql-tools/executor-legacy-ws previously hardcoded rejectUnauthorized: false when creating WebSocket connections over WSS. This disabled TLS certificate validation, allowing a network-positioned attacker to perform a Man-in-the-Middle (MITM) attack against applications that use this executor with a wss:// endpoint. Credentials passed via connectionParams or headers could be intercepted, and subscription data could be tampered with. Who is impacted: Applications using @graphql-tools/executor-legacy-ws (directly or via @graphql-tools/url-loader with SubscriptionProtocol.LEGACY_WS) to connect to a …