high8.2
CVE-2026-118262
Echo: WebSocket proxy can retain connections and handlers after client disconnect
Impact
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.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| go | github.com/labstack/echo/v4 | >= 4.15.0, < 4.16.1 | 4.16.1 |
| go | github.com/labstack/echo/v5 | >= 5.0.0, < 5.4.1 | 5.4.1 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-9969-6676-49h5
- https://github.com/labstack/echo/security/advisories/GHSA-9969-6676-49h5
- https://github.com/labstack/echo/commit/1855061e572ae9dab727c811d8382f266bfbaaec
- https://github.com/labstack/echo/commit/3fb0ba7e17645bb65611e2a08875d0a2f65c421f
- https://github.com/labstack/echo/releases/tag/v4.16.1
- https://github.com/labstack/echo/releases/tag/v5.4.1