CVE-2026-118651 Echo: Reverse Proxy Forwards Attacker-Supplied X-Real-IP to Upstream by Default
- Exploited in the wild
- Not known
- Fix
- Available
What is CVE-2026-118651?
CVE-2026-118651 is a medium-severity vulnerability in labstack echo, published on 28 Oct 2026.
Official description
Echo is a Go web framework. From 4.0.0 until 5.4.0, the Proxy middleware can preserve an attacker-supplied X-Real-IP header and forward it to an upstream service when Echo.IPExtractor is not configured. A remote client can therefore make upstream services receive a spoofed client address, undermining IP-based access controls, rate limiting, audit logging, or geographic restrictions that trust Echo's forwarded identity. This issue is fixed in Echo 5.4.0.
Weakness: CWE-346
Which versions are affected by CVE-2026-118651?
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 4.0.0 to 4.16.2 | None |
github.com/labstack/echo/v4 Go | From 4.0.0 to 4.16.2 | None |
github.com/labstack/echo/v5 Go | All versions | 5.4.0 |
github.com/labstack/echo/v5 Go | All versions | 5.4.0 |
How do I fix CVE-2026-118651?
Upgrade to a fixed version.
Is CVE-2026-118651 being exploited?
There is no known exploitation of CVE-2026-118651 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-118651, GHSA-99jh-6h7p-pp36, UBUNTU-CVE-2026-118651.