# CVE-2026-54464: Faye websocket-driver-ruby resource limit bypass in permessage-deflate

Source: https://junglewise.ai/threats/cve-2026-54464-faye-websocket-driver-ruby-resource-limit-bypass-in-permessage  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-07-17. Updated: 2026-07-17  
License: CC BY 4.0 with a link back

CVE-2026-54464 · Severity: medium · CVSS 4 · Published 2026-07-17

A vulnerability in a Ruby WebSocket library could allow an attacker to bypass configured message size limits when compression is enabled. By sending specially crafted compressed messages, an attacker can force the server or client to process much larger amounts of data than intended. This can lead to excessive memory or CPU consumption, potentially causing service instability or crashes.

Technologies: [websocket-driver (RubyGems)](https://junglewise.ai/threats/technologies/websocket-driver). Vendors: [RubyGems](https://junglewise.ai/threats/vendors/rubygems).

## Quick answers

**Is CVE-2026-54464 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-54464 being exploited in the wild.

**How severe is CVE-2026-54464?** Medium severity, with a CVSS score of 4, published 17 July 2026.

**Which products and versions are affected?** websocket-driver (RubyGems) < 0.8.1, ECOSYSTEM:introduced=0,fixed=0.8.1.

**Is there a fix for CVE-2026-54464?** Yes. websocket-driver (RubyGems): upgrade to 0.8.1 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-54464 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-54464?** Check whether you run websocket-driver (RubyGems) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- websocket-driver (RubyGems): upgrade to 0.8.1 or later

  ```sh
  bundle update websocket-driver
  ```


## Technical details

A resource exhaustion vulnerability (CWE-770) exists in websocket-driver-ruby when used with the 'permessage-deflate' extension. The library validates the maximum message size against the compressed frame length header rather than the post-decompression payload size. An attacker can exploit this by sending highly compressed WebSocket frames that expand significantly upon decompression, bypassing '@max_length' restrictions. This can lead to uncontrolled memory allocation and denial-of-service. The issue is fixed in version 0.8.1 by implementing length checks after extension processing.

## Affected products

- faye websocket-driver-ruby < 0.8.1

## Identifiers

- CVE-2026-54464
- GHSA-33ph-fccm-39pj

## Timeline

- 2026-06-04: advisory: GitHub Security Advisory published
- 2026-07-17: disclosed: NVD publication date
- 2026-08-01: patched: Fixed in version 0.8.1

## References

- [https://github.com/faye/websocket-driver-ruby/commit/fa8641724f10bf3273585f1dcf9041f540bbd036](https://github.com/faye/websocket-driver-ruby/commit/fa8641724f10bf3273585f1dcf9041f540bbd036)
- [https://github.com/faye/websocket-driver-ruby/security/advisories/GHSA-33ph-fccm-39pj](https://github.com/faye/websocket-driver-ruby/security/advisories/GHSA-33ph-fccm-39pj)

## Related threats

- [faye websocket-driver-ruby denial of service via malformed Host header](https://junglewise.ai/threats/cve-2026-61666-faye-websocket-driver-ruby-denial-of-service-via-malformed-host)
- [faye websocket-driver memory exhaustion in HTTP header parser](https://junglewise.ai/threats/cve-2026-54465-faye-websocket-driver-memory-exhaustion-in-http-header-parser)
- [faye websocket-driver-ruby memory exhaustion in draft protocol handler](https://junglewise.ai/threats/cve-2026-54463-faye-websocket-driver-ruby-memory-exhaustion-in-draft-protocol)