Echo is a Go web framework. From 4.0.0 until 4.16.1 and 5.4.1, Echo's Proxy middleware selects a raw tunnel from a client WebSocket upgrade request before verifying that the configured upstream accepted the upgrade. If the upstream rejects the upgrade with an ordinary keep-alive response, later HTTP requests on the connection are sent directly to that upstream without passing through Echo's router or route-specific middleware. This can bypass authentication or authorization enforced only by Echo routes, but requires an accessible proxy route, a cooperating rejected-upgrade response, and a target without independent upstream authorization. This issue is fixed in 4.16.1 and 5.4.1.

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Source ID Title
Github GHSA Github GHSA GHSA-cxf3-9h37-7rr8 Echo: Rejected WebSocket upgrades can bypass Echo route-level access controls
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Wed, 28 Oct 2026 21:00:00 +0000

Type Values Removed Values Added
First Time appeared Labstack
Labstack echo
Vendors & Products Labstack
Labstack echo

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

Type Values Removed Values Added
Description Echo is a Go web framework. From 4.0.0 until 4.16.1 and 5.4.1, Echo's Proxy middleware selects a raw tunnel from a client WebSocket upgrade request before verifying that the configured upstream accepted the upgrade. If the upstream rejects the upgrade with an ordinary keep-alive response, later HTTP requests on the connection are sent directly to that upstream without passing through Echo's router or route-specific middleware. This can bypass authentication or authorization enforced only by Echo routes, but requires an accessible proxy route, a cooperating rejected-upgrade response, and a target without independent upstream authorization. This issue is fixed in 4.16.1 and 5.4.1.
Title Echo: Rejected WebSocket upgrades can bypass Echo route-level access controls
Weaknesses CWE-444
CWE-863
References
Metrics cvssV4_0

{'score': 9.1, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-10-28T19:03:01.533Z

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

Link: CVE-2026-118264

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-10-28T19:17:31.237

Modified: 2026-10-28T19:17:31.237

Link: CVE-2026-118264

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-10-28T21:00:23Z

Weaknesses