Vulnerability in Faye Websocket-Driver
CVE-2026-54466
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.
EPSS: 0.002 (12.5th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.
Affected products
- Faye Websocket-driver
- Faye Websocket-driver-node — versions < 0.7.5
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Vendor Advisory)
- security-advisories@github.com (Patch, x_refsource_MISC)
Frequently asked questions
- What is CVE-2026-54466?
- CVE-2026-54466 is a high-severity vulnerability in Faye Websocket-Driver, classified under Improper Handling of Length Parameter Inconsistency. CVSS score: 7.5/10. Published 2026-07-17.
- How severe is CVE-2026-54466?
- High severity. CVSS v3 base score is 7.5 out of 10.