CVE-2026-54466

CRITICALPre-NVD 9.29.2—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.2 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3%, top 82% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
9.2EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 9.2Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

websocket-driver is a WebSocket protocol handler with pluggable I/O. Prior to 0.7.5, the frame format in draft versions of the WebSocket protocol includes a length header that allows an arbitrarily large integer to be encoded as a sequence of bytes with the high bit set. By sending an indefinite sequence of bytes with values 0x80 or above, a client can make the server parse these bytes into an ever-growing integer in lib/websocket/driver/draft75.js; because JavaScript numbers are 64-bit floating point values, this number will eventually lose precision and lead to the subsequent payload being parsed incorrectly. This issue is fixed in version 0.7.5.

CVSS v3
9.2
EG Score
9.2(medium)
EG Risk
57(Track)
EG Risk 57/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity92% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
18%
KEV
Not listed

Published

July 15, 2026

Last Modified

July 23, 2026

Advisory Details (2)

Auto-updated Jul 17, 2026
Patch available. Sources: github_commit, github.
github Patch Available

Message corruption via abuse of protocol length headers · Advisory · faye/websocket-driver-node · GitHub

Affected: version 0.7.5 by rejecting the message if the

https://github.com/faye/websocket-driver-node/security/advisories/GHSA-xv26-6w52-cph6
github_commit

commit 5b197ca874da (faye/websocket-driver-node)

Fix landed in faye/websocket-driver-node commit 5b197ca874da — awaiting tagged release

https://github.com/faye/websocket-driver-node/commit/5b197ca874dab58e96cacad8a3c256797d804680

Vendor Advisories for CVE-2026-54466(1)

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

Affected Packages

(1 across 1 ecosystem)
npm(1)
PackageVulnerable rangeFixed inDependents
websocket-driver—0.7.5—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 11× in last 7d / 18× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-26 15:12 UTCEG score recompute
  2. 2026-07-26 14:54 UTCEPSS rescore
  3. 2026-07-26 11:29 UTCEG score recompute
  4. 2026-07-26 04:39 UTCEG score recompute
  5. 2026-07-25 14:18 UTCEPSS rescore
  6. 2026-07-24 14:18 UTCEPSS rescore
  7. 2026-07-23 14:18 UTCEPSS rescore
  8. 2026-07-23 03:19 UTCEG score recompute
  9. 2026-07-22 14:08 UTCEPSS rescore
  10. 2026-07-21 15:25 UTCEPSS rescore
  11. 2026-07-20 17:08 UTCEPSS rescore
  12. 2026-07-19 14:31 UTCEPSS rescore
  13. 2026-07-19 14:31 UTCEPSS rescore
  14. 2026-07-19 02:36 UTCEG score recompute
  15. 2026-07-19 02:29 UTCEPSS rescore
  16. 2026-07-17 21:00 UTCEG score recompute▲ 9.20
  17. 2026-07-17 20:59 UTCMITRE cvelistV5CVSS v3 → 9.2 · CVSS v4 → 9.2
  18. 2026-07-15 22:19 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-54466?
CVE-2026-54466 is a critical vulnerability published on July 15, 2026. websocket-driver is a WebSocket protocol handler with pluggable I/O. Prior to 0.7.5, the frame format in draft versions of the WebSocket protocol includes a length header that allows an arbitrarily large integer to be encoded as a sequence of bytes with the high bit set. By sending an indefinite…
When was CVE-2026-54466 disclosed?
CVE-2026-54466 was first published in the National Vulnerability Database on July 15, 2026, with the most recent update on July 23, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-54466 actively exploited?
CVE-2026-54466 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 82.0% of all scored CVEs.
What is the CVSS score of CVE-2026-54466?
CVE-2026-54466 has a CVSS v3 base score of 9.2 (NVD).
How do I remediate CVE-2026-54466?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-54466, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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