CVE-2026-118262 Echo: WebSocket proxy can retain connections and handlers after client disconnect
- Exploited in the wild
- Not known
- Fix
- Available
What is CVE-2026-118262?
CVE-2026-118262 is a high-severity vulnerability in labstack echo, published on 28 Oct 2026.
Official 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.
Weakness: CWE-772
Which versions are affected by CVE-2026-118262?
4 open source packages ship an affected version, including github.com/labstack/echo/v4 and github.com/labstack/echo/v5.
| Package | Affected | Fixed in |
|---|---|---|
github.com/labstack/echo/v4 Go | From 4.15.0 | 4.16.1 |
github.com/labstack/echo/v4 Go | From 4.15.0 | 4.16.1 |
github.com/labstack/echo/v5 Go | From 5.0.0 | 5.4.1 |
github.com/labstack/echo/v5 Go | From 5.0.0 | 5.4.1 |
How do I fix CVE-2026-118262?
Upgrade github.com/labstack/echo/v4 to 4.16.1 or later.
Is CVE-2026-118262 being exploited?
There is no known exploitation of CVE-2026-118262 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-118262, ECHO-ec06-f360-e7e1, GHSA-9969-6676-49h5, ROOT-APP-GOBINARY-GHSA-9969-6676-49h5, UBUNTU-CVE-2026-118262.