CVE-2026-118262

high

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.

References

https://github.com/labstack/echo/security/advisories/GHSA-9969-6676-49h5

https://github.com/labstack/echo/releases/tag/v5.4.1

https://github.com/labstack/echo/releases/tag/v4.16.1

https://github.com/labstack/echo/commit/3fb0ba7e17645bb65611e2a08875d0a2f65c421f

https://github.com/labstack/echo/commit/1855061e572ae9dab727c811d8382f266bfbaaec

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-112394

Details

Source: Mitre, NVD

Published: 2026-10-28

Updated: 2026-10-28

Risk Information

CVSS v2

Base Score: 5

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:P

Severity: Medium

CVSS v3

Base Score: 7.5

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Severity: High

CVSS v4

Base 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

Severity: High