websocket-driver: Resource limit bypass via message compression

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

6.3 · 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 · score source

EPSS

• CVE-2026-54464: 0.45% estimated exploitation activity in the next 30 days; percentile 38.73 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Impact If this library is used in tandem 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. This is because this limit is checked against the message frames' length headers, which give the size of the compressed data, not the size after decompression. This can lead to applications accepting larger messages than expected and exceeding their intended resource usage. Patches The issue has been patched in version 0.8.1, by checking the length of messages after they are processed by incoming extensions. All users should upgrade to this version. Workarounds No known workarounds exist. Acknowledgements This issue was discovered and reported by Pranjali Thakur, DepthFirst Security Research Team.

Published by the source

15 Jul 2026, 22:03 UTC

Last modified by the source

17 Aug 2026, 16:15 UTC

Source last checked

26 Oct 2026, 15:52 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-33ph-fccm-39pj

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# Patch Next advisory brief: CVE-2026-54464

Advisory: websocket-driver: Resource limit bypass via message compression
IDs: CVE-2026-54464, GHSA-33ph-fccm-39pj
Record: https://patchnext.com/advisories/cve-2026-54464 (revision 1, source checked 26 Oct 2026, 15:52 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: websocket-driver 0.8.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- RubyGems websocket-driver: affected < 0.8.1; fixed in 0.8.1

## Suggested inspection (read-only)
- RubyGems websocket-driver: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on websocket-driver.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-33ph-fccm-39pj (GitHub-reviewed advisory GHSA-33ph-fccm-39pj lists affected ranges: RubyGems websocket-driver >=0 <0.8.1)

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