Echo Web 框架 WebSocket 升級被拒時可繞過路由層認證 - CVE-2026-118264
CVE-2026-118264 - Echo: Rejected WebSocket upgrades can bypass Echo route-level access controls
Echo Web 框架在 4.0.0 以至 4.16.1 與 5.4.1 版本中，Proxy 中介軟體在驗證上游升級前即選擇 WebSocket 隧道，若上游以普通 keep‑alive 回應拒絕升級，後續 HTTP 請求將直接送往上游，繞過 Echo 路由與中介層，可能導致認證或授權被繞過。
此漏洞允許 WebSocket 升級被拒時，繞過 Echo 路由層的認證與授權，建議立即升級至 4.16.1 或 5.4.1 以修補此安全缺口。
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.
Impact
Affected Products
The following products are affected by CVE-2026-118264
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
| ID | Vendor | Product | Action |
|---|---|---|---|
| 1 | Labstack | echo |
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 4.0 | CRITICAL | [email protected] |
Update Echo's Proxy middleware to a fixed version to prevent bypassing authentication/authorization checks.
- Update Echo to version 4.16.1 or later.
- Update Echo to version 5.4.1 or later.
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The following table lists the changes that have been made to the
CVE-2026-118264 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by [email protected]
十月. 28, 2026
Action Type Old Value New Value Added 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. Added CVSS V4.0 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 Added CWE CWE-444 Added CWE CWE-863 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/118xxx/CVE-2026-118264.json">CVE-2026-118264</a> Added Reference https://github.com/labstack/echo/commit/1855061e572ae9dab727c811d8382f266bfbaaec Added Reference https://github.com/labstack/echo/commit/3fb0ba7e17645bb65611e2a08875d0a2f65c421f Added Reference https://github.com/labstack/echo/releases/tag/v4.16.1 Added Reference https://github.com/labstack/echo/releases/tag/v5.4.1 Added Reference https://github.com/labstack/echo/security/advisories/GHSA-cxf3-9h37-7rr8
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.