Labstack Echo up to 4.16.0/5.4.0 Proxy Middleware denial of service

Summaryinfo

A vulnerability classified as problematic was found in Labstack Echo up to 4.16.0/5.4.0. This impacts an unknown function of the component Proxy Middleware. Such manipulation leads to denial of service. This vulnerability is uniquely identified as CVE-2026-118262. The attack can be launched remotely. No exploit exists. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in Labstack Echo up to 4.16.0/5.4.0 and classified as problematic. Affected by this issue is an unknown function of the component Proxy Middleware. The manipulation with an unknown input leads to a denial of service vulnerability. Using CWE to declare the problem leads to CWE-404. The product does not release or incorrectly releases a resource before it is made available for re-use. Impacted is availability. CVE summarizes:

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.

The advisory is available at github.com. This vulnerability is handled as CVE-2026-118262 since 10/27/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. The technical details are unknown and an exploit is not available. This vulnerability is assigned to T1499 by the MITRE ATT&CK project.

Upgrading to version 4.16.1 or 5.4.1 eliminates this vulnerability.

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Vendor

• Labstack

Name

• Echo

Version

• 4.0
• 4.1
• 4.2
• 4.3
• 4.4
• 4.5
• 4.6
• 4.7
• 4.8
• 4.9
• 4.10
• 4.11
• 4.12
• 4.13
• 4.14
• 4.15
• 4.16.0
• 5.0
• 5.1
• 5.2
• 5.3
• 5.4.0

Website

• Product: https://github.com/labstack/echo/

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