websocket-driver: Memory exhaustion in HTTP header parser

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-2026-54465: 0.49% estimated exploitation activity in the next 30 days; percentile 42.05 (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 to implement a WebSocket server on top of a TCP server (rather than an HTTP server or framework) using the WebSocket::Driver.server() method, or, if it is used to complement a WebSocket client, then a peer can make a single connection consume an unbounded amount of memory by sending an HTTP request or response with a never-ending list of headers. This can lead to the receiving process running out of memory. Patches The issue has been patched in version 0.8.1, by limiting the total size of HTTP request/response lines and headers accepted by the parser to 32 kB. 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, 22:05 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-8j3g-f24p-4mpw

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# Patch Next advisory brief: CVE-2026-54465

Advisory: websocket-driver: Memory exhaustion in HTTP header parser
IDs: CVE-2026-54465, GHSA-8j3g-f24p-4mpw
Record: https://patchnext.com/advisories/cve-2026-54465 (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-8j3g-f24p-4mpw (GitHub-reviewed advisory GHSA-8j3g-f24p-4mpw lists affected ranges: RubyGems websocket-driver >=0 <0.8.1)

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