CVE-2026-118656 Echo: Open Redirect via Control-Character Prefix Defeating sanitizeURI
- Exploited in the wild
- Not known
- Fix
- Available
What is CVE-2026-118656?
CVE-2026-118656 is a medium-severity vulnerability in labstack echo, published on 28 Oct 2026.
Official description
Echo is a Go web framework. Prior to 4.16.0 and 5.4.0, sanitizeURI checks only the first two bytes of a redirect target before deciding whether it begins with an absolute-path separator pair. When AddTrailingSlash or RemoveTrailingSlash is configured with a redirect status, a slash, TAB, separator path form can evade the guard, be emitted in the Location header, and be normalized by a browser into an attacker-controlled host. This issue is fixed in 4.16.0 and 5.4.0.
Weakness: CWE-601
Which versions are affected by CVE-2026-118656?
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 | All versions | 4.16.0 |
github.com/labstack/echo/v4 Go | All versions | 4.16.0 |
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-2026-118656?
Upgrade github.com/labstack/echo/v4 to 4.16.0 or later.
Is CVE-2026-118656 being exploited?
There is no known exploitation of CVE-2026-118656 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-118656, ECHO-e06f-d2f8-f714, GHSA-v753-g4cw-jm48, UBUNTU-CVE-2026-118656.