Echo: Rejected WebSocket upgrades can bypass Echo route-level access controls (labstack echo)
At a glance
- Source
- NVD
- EPSS
- EPSS 0.43 % · percentile 37 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- GitHub_M
- NVD status
- Undergoing Analysis
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.
Weaknesses (CWE)
References
- https://github.com/labstack/echo/security/advisories/GHSA-cxf3-9h37-7rr8
- 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
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 4.0 | CRITICAL 9.1 | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N | GitHub_M |
| CVSS 4.0 | CRITICAL 9.1 | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X | NVD · security-advisories@github.com (Secondary) |
Advisories
- GHSA-cxf3-9h37-7rr8 — Echo: Rejected WebSocket upgrades can bypass Echo route-level access controls
European references
- ENISA EUVD · EUVD-2026-112396
- GCVE · GCVE-0-2026-118264
Affected products
| Product | Versions |
|---|---|
| labstack · echo | affected >= 4.0.0, < 4.16.1 ; affected >= 5.0.0, < 5.4.1 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |