CVE-2026-118264

Name	CVE-2026-118264
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.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
golang-github-labstack-echo (PTS)	bookworm	4.2.1-3	vulnerable
	forky, sid, trixie	4.12.0-1	vulnerable

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
golang-github-labstack-echo	source	(unstable)	(unfixed)

Notes

https://github.com/labstack/echo/security/advisories/GHSA-cxf3-9h37-7rr8
Fixed by: https://github.com/labstack/echo/commit/3fb0ba7e17645bb65611e2a08875d0a2f65c421f (v4.16.1)
Fixed by: https://github.com/labstack/echo/commit/1855061e572ae9dab727c811d8382f266bfbaaec (v5.4.1)