VulnerabilityPublished 28 Oct 2026

CVE-2026-118665: GraphQL Tools · Per-request connection parameters persist into later users' WebSocket authentications

Affects @graphql-tools/executor-legacy-wsSource GCVE Database

Authoritative record:CVE-2026-118665· High 8.2

Not known to be exploited · CVSS 8.2 High : upgrade to 1.1.36 soon.

Data as of 28 Oct 2026, 22:12 UTC

CVSS 4.0 base score

8.2High

How severe the flaw is on the 0–10 CVSS scale.

Patch: Available – fixed in 1.1.36

CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

Attack Vector: Network
Attack Complexity: High
Attack Requirements: Present
Privileges Required: None
User Interaction: None
Vulnerable system confidentiality: High
Vulnerable system integrity: None
Vulnerable system availability: None
Subsequent system confidentiality: None
Subsequent system integrity: None
Subsequent system availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, up to and including the entire Internet. Such a vulnerability is often termed “remotely exploitable” and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: High: The successful attack depends on the evasion or circumvention of security-enhancing techniques in place that would otherwise hinder the attack. These include: Evasion of exploit mitigation techniques, for example, circumvention of address space randomization (ASLR) or data execution prevention (DEP) must be performed for the attack to be successful; Obtaining target-specific secrets. The attacker must gather some target-specific secret before the attack can be successful. A secret is any piece of information that cannot be obtained through any amount of reconnaissance. To obtain the secret the attacker must perform additional attacks or break otherwise secure measures (e.g. knowledge of a secret key may be needed to break a crypto channel). This operation must be performed for each attacked target.
Attack Requirements: Present: The successful attack depends on the presence of specific deployment and execution conditions of the vulnerable system that enable the attack. These include: a race condition must be won to successfully exploit the vulnerability (the successfulness of the attack is conditioned on execution conditions that are not under full control of the attacker, or the attack may need to be launched multiple times against a single target before being successful); the attacker must inject themselves into the logical network path between the target and the resource requested by the victim (e.g. vulnerabilities requiring an on-path attacker).
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system confidentiality: High: There is a total loss of confidentiality, resulting in all information within the Vulnerable System being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact. For example, an attacker steals the administrator's password, or private encryption keys of a web server.
Vulnerable system integrity: None: There is no loss of integrity within the Vulnerable System.
Vulnerable system availability: None: There is no impact to availability within the Vulnerable System.
Subsequent system confidentiality: None: There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
Subsequent system integrity: None: There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 28 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade @graphql-tools/executor-legacy-ws to 1.1.36.

Affected software

Product	Affected	Fixed in
npm@graphql-tools/executor-legacy-ws	Affected <1.1.36	Fixed in 1.1.36

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

Description

# Stale authentication state in `@graphql-tools/executor-legacy-ws`: per-request `extensions.connectionParams` persist in executor closure state and are replayed in a later caller's `connection_init` ## Report metadata | Field | Value | | --- | --- | | Package | `@graphql-tools/executor-legacy-ws` (npm, `pkg:npm/%40graphql-tools/executor-legacy-ws`) | | Repository | https://github.com/ardatan/graphql-tools | | Component | `buildWSLegacyExecutor` (`packages/executors/legacy-ws/src/index.ts`) | | Vulnerability class | Stale authentication state / credential reuse across requests | | Verified against | Commit `b5d1c36ebb8ed3868260ffee5bbcbb423ad5c1f1`; npm release `1.1.33` installed and exercised. During validation the same behaviour was also observed on the current latest release `1.1.35`, and the unreset closure is still present on `master`. | | API surface | Public documented API (`buildWSLegacyExecutor`, and `request.extensions.connectionParams` on the returned executor) | | Affected in default configuration | Yes — the factory returns a general, reusable `Executor` with no per-identity or single-use restriction, and no supported teardown clears the retained parameters. | Version note: the originally recorded affected range was `<= 1.1.33`. Validation showed that range understates exposure — the same proof of concept leaks identically on `1.1.35`. ## Summary `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 entirely. The consumer-side shape is a shared executor that forwards per-user credentials. When one long-lived executor serves multiple principals — the schema-stitching, gateway, or mesh pattern where each `ExecutionRequest` supplies its own `extensions.connectionParams` — a request that omits the auth key is sent to the downstream server with the previous caller's `Authorization`/tenant values in its `connection_init`, so the downstream server authenticates the later caller as the earlier user. Behaviour of the neighbouring state in the same file: - WebSocket handle (`websocket`) → reset on teardown in `cleanupWebsocket`, [lines 78-88](https://github.com/ardatan/graphql-tools/blob/b5d1c36ebb8ed3868260ffee5bbcbb423ad5c1f1/packages/executors/legacy-ws/src/index.ts#L78-L88) - Per-request `connectionParams` merge, present case → applied as documented, [lines 93-101](https://github.com/ardatan/graphql-tools/blob/b5d1c36ebb8ed3868260ffee5bbcbb423ad5c1f1/packages/executors/legacy-ws/src/index.ts#L93-L101) - `executorConnectionParams` closure object → **never reset; survives socket teardown and is re-sent on the next connection, [line 32](https://github.com/ardatan/graphql-tools/blob/b5d1c36ebb8ed3868260ffee5bbcbb423ad5c1f1/packages/executors/legacy-ws/src/index.ts#L32) and [line 54](https://github.com/ardatan/graphql-tools/blob/b5d1c36ebb8ed3868260ffee5bbcbb423ad5c1f1/packages/executors/legacy-ws/src/index.ts#L54)** ## Impact A caller who supplies no credentials (or lower-privileged ones) can have its downstream GraphQL subscription executed under a previous user's retained token or tenant value, and can receive data that its own `connection_init` would not authorize. The credential itself is never disclosed to the attacker — it reaches the sink through closure storage, not because the attacker knows it — but the downstream authorization it represents is. The new capability versus safe behaviour: without this bug, an anonymous request would open a connection whose `connection_init` contains only base options plus that request's own parameters, and the downstream server would treat it as anonymous. With it, the anonymous request inherits the victim's authorization. Validation also showed partial-overwrite merging: a later caller supplying only `{tenant: "<attacker tenant>"}` gets the victim's `Authorization` retained alongside its own tenant, i.e. an attacker-chosen tenant authenticated with someone else's bearer token. Scoring note: **not scored.** No CVSS vector accompanies this finding, and exploitability depends on the consuming application's data flow rather than on the library alone. Consumers that construct a fresh executor per request are **not** affected — the in-repository `UrlLoader` wrapper ([`packages/loaders/url/src/index.ts:172-182`](https://github.com/ardatan/graphql-tools/blob/b5d1c36ebb8ed3868260ffee5bbcbb423ad5c1f1/packages/loaders/url/src/index.ts#L172-L182)) builds a new executor for each request and therefore does not exhibit the persistence. The exposure is to applications that use the

CWE-613Insufficient Session Expiration (opens in a new tab)
Base weaknessOWASP Top 10 A07:2025: Authentication Failures (opens in a new tab)
According to WASC, "Insufficient Session Expiration is when a web site permits an attacker to reuse old session credentials or session IDs for authorization."
Implementation
Set sessions/credentials expiration date.
OWASP Cheat Sheets
OWASP Authentication (opens in a new tab)
OWASP ASVS 4.0.3
V2.8.1 (opens in a new tab)
V2.8.6 (opens in a new tab)
V3.6.1 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

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Affected software

Description

WeaknessesCWE-613

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