CVE-2026-118666

MEDIUMPre-NVD 6.06.0
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to the CVSS score beside it.

This medium-severity CVE scores 6.0 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3% (27th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from a secondary CVSS source
Sources: EPSS, a secondary CVSS source
Elevated

Also known asEUVD-2026-112473 (ENISA EUVD) · GHSA-mp66-8ww2-pcwm (GitHub Security Advisories)Source: ENISA EUVD

6.0EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (the SSVC decision on this page).
  • CISA's Vulnrichment rates exploitation as PoC; EchelonGraph holds no exploit-code reference for it
CISA-KEV: Not listedEPSS PROB: 0.3%CVSS: 6.0Exploit: No code on recordExposed services: Not assessed

A fix is available — apply it.

GraphQL Tools provides utilities for building, stitching, and mocking GraphQL schemas. Prior to version 1.1.36 of the GraphQL Tools legacy WebSocket executor package, buildWSLegacyExecutor in packages/executors/legacy-ws/src/index.ts reuses one WebSocket and replaces its single websocket.onmessage handler whenever a new overlapping subscription starts. The handler delivers LEGACY_WS.DATA frames to the newest observer without comparing data.id with the subscription operation id, so a caller using the same executor can receive another user's authorized subscription payload while the earlier caller's stream is starved. This issue is fixed in version 1.1.36 of the GraphQL Tools legacy WebSocket executor package.

CVSS
6.0
EG Score
6.0MEDIUMmedium confidence
EG Risk
58
EG Risk 58/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity60% × 45%
Impact severity (EG Severity): CVSS 6.0 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation40% × 40%
EchelonGraph's fixed weight for EG-KEV Tier 3 (Elevated): a constant, not a probability.
Automatability100% × 15%
CISA's SSVC Automatable value: yes (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Attend at high (mission-essential systems).
Exploitation public PoC (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
0.3%
EPSS %ILE
27th
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (6.0): severity, escalated by confirmed exploitation. This CVE's 6.0 is its impact severity (EG Severity), not escalated.

EG Severity
6.0 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.a secondary CVSS source
EG Likelihood
0.3% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-10). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track at medium mission impactTrack at low or medium mission impact; Attend at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; 60 days if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Attend at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation public PoC (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; 60 days if it is not.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

October 28, 2026

Last Modified

November 3, 2026

Advisory Details (3)

Auto-updated Nov 3, 2026
🔬 Proof of concept available. Patch available. Sources: github_commit, github_pr, github.
GitHub advisoryMentions a patch (unverified)🟡 PoC Available

Shared legacy executor routes one subscription's results to a different caller · Advisory · ardatan/graphql-tools · GitHub

https://github.com/ardatan/graphql-tools/security/advisories/GHSA-mp66-8ww2-pcwm
GitHub pull request

fix(executor-legacy-ws): isolate per-request auth and subscription results

Fix merged in ardatan/graphql-tools PR #8480 on 2026-09-30 — awaiting tagged release

https://github.com/ardatan/graphql-tools/pull/8480
GitHub commit

commit c2f226e6f682 (ardatan/graphql-tools)

Fix landed in ardatan/graphql-tools commit c2f226e6f682 — awaiting tagged release

https://github.com/ardatan/graphql-tools/commit/c2f226e6f68236be9e4a577f29faeaa92547458b

Vendor Advisories for CVE-2026-118666(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(1)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
npm@graphql-tools/executor-legacy-ws @ 1.1.36 (fixes <= 1.1.35)—ghsa

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(1 across 1 ecosystem)
npm(1)
PackageVulnerable rangeFix by version rangeDependents
@graphql-tools/executor-legacy-ws—
  • every version up to 1.1.36: fixed in 1.1.36
—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 8× in last 7d / 23× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed its CVE.org record (CNA or CISA ADP). An arrow marks a change the record states ("CVSS → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). "EchelonGraph re-scored" is our own recompute of this CVE's score, not an update from a source, and is not counted in the refreshes above. Most recent first.

  1. 2026-11-13 16:50 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  2. 2026-11-12 16:33 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  3. 2026-11-11 16:38 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  4. 2026-11-11 06:55 UTCEchelonGraph re-scored
  5. 2026-11-11 06:55 UTCGHSA enrichmentGHSA-mp66-8ww2-pcwm · GitHub severity MODERATE
  6. 2026-11-10 16:42 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  7. 2026-11-09 16:34 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  8. 2026-11-08 16:38 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  9. 2026-11-07 16:38 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  10. 2026-11-06 16:36 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  11. 2026-11-05 16:36 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  12. 2026-11-04 16:34 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  13. 2026-11-04 01:48 UTCEchelonGraph re-scored
  14. 2026-11-04 01:48 UTCGHSA enrichmentGHSA-mp66-8ww2-pcwm · GitHub severity MODERATE
  15. 2026-11-03 16:46 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  16. 2026-11-03 00:26 UTCEchelonGraph re-scored
  17. 2026-11-03 00:26 UTCGHSA enrichmentGHSA-mp66-8ww2-pcwm · GitHub severity MODERATE
  18. 2026-11-03 00:10 UTCEchelonGraph re-scored
  19. 2026-11-03 00:10 UTCGHSA enrichmentGHSA-mp66-8ww2-pcwm · GitHub severity MODERATE
  20. 2026-11-02 16:44 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  21. 2026-11-01 16:33 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  22. 2026-11-01 07:59 UTCGHSA enrichmentGHSA-mp66-8ww2-pcwm · GitHub severity MODERATE
  23. 2026-11-01 07:59 UTCEchelonGraph re-scored
  24. 2026-10-31 16:32 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  25. 2026-10-30 16:33 UTCEPSS rescoreEPSS 0.3% · 26th percentile
Show 5 more
  1. 2026-10-29 16:32 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  2. 2026-10-28 21:27 UTCEchelonGraph re-scored
  3. 2026-10-28 21:01 UTCENISA EUVD ID recordedEUVD-2026-112473 · Source: ENISA EUVD
  4. 2026-10-28 20:49 UTCEchelonGraph re-scoredFirst assessed: 6.0 MEDIUM
  5. 2026-10-28 20:48 UTCMITRE cvelistV5first tracked

Related CVEs(same product + same CWE)

Same product

2 shown

npm:@graphql-tools/executor-legacy-ws

Frequently asked(5)

What is CVE-2026-118666?
CVE-2026-118666 is a medium-severity vulnerability; its CVE record was published on October 28, 2026. GraphQL Tools provides utilities for building, stitching, and mocking GraphQL schemas. Prior to version 1.1.36 of the GraphQL Tools legacy WebSocket executor package, buildWSLegacyExecutor in packages/executors/legacy-ws/src/index.ts reuses one WebSocket and replaces its single websocket.onmessage…
When was the CVE record for CVE-2026-118666 published?
The CVE record for CVE-2026-118666 was published on October 28, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of November 3, 2026; the record at its source may have been updated since.
Is CVE-2026-118666 actively exploited?
CVE-2026-118666 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.3% probability of exploitation in the next 30 days (27th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-118666?
CVE-2026-118666 has a CVSS base score of 6.0 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-118666?
A fix for CVE-2026-118666 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-118666 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-118666

Explore →

Is Your Infrastructure Affected by CVE-2026-118666?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Book a Demo →Browse All CVEs