Vulnerability 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.
Related Weaknesses (CWE)
References
- 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
- https://github.com/labstack/echo/security/advisories/GHSA-9969-6676-49h5
FAQ
What is CVE-2026-118262?
CVE-2026-118262 is a documented vulnerability. 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 ups...
How severe is CVE-2026-118262?
CVSS scoring is not yet available for CVE-2026-118262. Check NVD for updates.
Is there a patch for CVE-2026-118262?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.