Echo is a Go web framework. From 4.15.0 until 4.16.1 and 5.4.1, Echo's Proxy middleware can retain a handler, copy goroutines, and network connections after a WebSocket client disconnects when the upstream keeps its connection open. The raw proxy waits for both copy directions without reliably closing the peer connection when one direction ends, including when a rejected upgrade response uses HTTP keep-alive. Repeated connections can accumulate resources and cause denial of service, depending on proxy-route accessibility, upstream behavior, and connection deadlines. This issue is fixed in 4.16.1 and 5.4.1.

Project Subscriptions

No data.

Advisories
Source ID Title
Github GHSA Github GHSA GHSA-9969-6676-49h5 Echo: WebSocket proxy can retain connections and handlers after client disconnect
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Wed, 28 Oct 2026 19:15:00 +0000

Type Values Removed Values Added
Description Echo is a Go web framework. From 4.15.0 until 4.16.1 and 5.4.1, Echo's Proxy middleware can retain a handler, copy goroutines, and network connections after a WebSocket client disconnects when the upstream keeps its connection open. The raw proxy waits for both copy directions without reliably closing the peer connection when one direction ends, including when a rejected upgrade response uses HTTP keep-alive. Repeated connections can accumulate resources and cause denial of service, depending on proxy-route accessibility, upstream behavior, and connection deadlines. This issue is fixed in 4.16.1 and 5.4.1.
Title Echo: WebSocket proxy can retain connections and handlers after client disconnect
Weaknesses CWE-772
References
Metrics cvssV4_0

{'score': 8.2, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}


Projects

Sign in to view the affected projects.

cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-10-28T19:00:12.315Z

Reserved: 2026-10-27T20:13:55.314Z

Link: CVE-2026-118262

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-10-28T19:17:30.950

Modified: 2026-10-28T19:17:30.950

Link: CVE-2026-118262

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses