Vulnerability · Published Oct 28, 2026 · Assigned by GitHub_M
CVE-2026-118262Echo: WebSocket proxy can retain connections and handlers after client disconnect
High 8.2
In plain English
A high-severity security flaw in echo from labstack. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 23% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | golang-github-labstack-echo | no fix listed | DEBIAN-CVE-2026-118262 |
| Debian:13 | golang-github-labstack-echo | no fix listed | DEBIAN-CVE-2026-118262 |
| Debian:14 | golang-github-labstack-echo | no fix listed | DEBIAN-CVE-2026-118262 |
| Go | github.com/labstack/echo/v4 | 4.16.1 | GHSA-9969-6676-49h5 |
| Go | github.com/labstack/echo/v4 | 4.16.1 | GO-2026-6838 |
| Go | github.com/labstack/echo/v5 | 5.4.1 | GHSA-9969-6676-49h5 |
| Go | github.com/labstack/echo/v5 | 5.4.1 | GO-2026-6838 |
| Ubuntu:22.04:LTS | golang-github-labstack-echo | no fix listed | UBUNTU-CVE-2026-118262 |
| Ubuntu:24.04:LTS | golang-github-labstack-echo | no fix listed | UBUNTU-CVE-2026-118262 |
| Ubuntu:26.04:LTS | golang-github-labstack-echo | no fix listed | UBUNTU-CVE-2026-118262 |
| Ubuntu:26.10 | golang-github-labstack-echo | no fix listed | UBUNTU-CVE-2026-118262 |
| Ubuntu:22.04:LTS | golang-github-labstack-echo.v2 | no fix listed | UBUNTU-CVE-2026-118262 |
| Ubuntu:22.04:LTS | golang-github-labstack-echo.v3 | no fix listed | UBUNTU-CVE-2026-118262 |
Affected products (as reported)
Weakness: CWE-772 · 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
References
- https://github.com/labstack/echo/security/advisories/GHSA-9969-6676-49h5 x_refsource_CONFIRM
- https://github.com/labstack/echo/commit/1855061e572ae9dab727c811d8382f266bfbaaec x_refsource_MISC
- https://github.com/labstack/echo/commit/3fb0ba7e17645bb65611e2a08875d0a2f65c421f x_refsource_MISC
- https://github.com/labstack/echo/releases/tag/v4.16.1 x_refsource_MISC
- https://github.com/labstack/echo/releases/tag/v5.4.1 x_refsource_MISC