Cyber Resilience

CVE-2026-54466

Faye Websocket-Driver ≤ 0.7.5

Published
17 July 2026
Modified
06 August 2026
Patch / advisory
View advisory
CVSS Score v4 9.2
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0026 18th percentile
Risk Priority 45 floored blend · peak EPSS

Summary

CVE-2026-54466 is a critical-severity Improper Handling of Length Parameter Inconsistency (CWE-130) vulnerability in Faye Websocket-Driver. Its CVSS base score is 9.2 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 18th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

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…

more

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.

CWE(s)
CWE-130

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
attack.mitre.org →
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
attack.mitre.org →
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-5265Shared CWE-130
CVE-2025-5514Shared CWE-130
CVE-2023-5393Shared CWE-130
CVE-2026-9054Shared CWE-130
CVE-2023-28964Shared CWE-130
CVE-2024-20416Shared CWE-130
CVE-2025-48022Shared CWE-130
CVE-2024-38010Shared CWE-130
CVE-2024-42460Shared CWE-130
CVE-2024-35313Shared CWE-130

Affected Assets

faye
websocket-driver
≤ 0.7.5

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V3.5.5
  • V4.2.1
  • V4.2.2

Mitigating Controls (NIST 800-53 r5) AI

SA-11 Developer Testing and Evaluation good match

Developer testing and evaluation can discover length-parameter inconsistencies through targeted parsing tests.

SI-10 Information Input Validation good match

Input validation enforces correct length-to-data consistency checks on parsed messages before processing.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly enforce length validation and input sanitization during coding and review.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.29 Security testing in development and acceptance mostly match
detects

Security testing in development can detect length-inconsistency vulnerabilities before deployment.

A.8.25 Secure development life cycle partial match
prevents

Secure development lifecycle mandates input validation and length checks that directly address inconsistent length fields.

A.8.26 Application security requirements partial match
prevents

Application security requirements include explicit rules for handling message lengths and data structures.

A.8.27 Secure system architecture and engineering principles partial match
prevents

Secure architecture principles require robust parsing and bounds checking to prevent length-related flaws.

A.8.28 Secure coding partial match
prevents

Secure coding standards directly prohibit improper length handling and enforce defensive parsing practices.

References