Open Redirect in Labstack Echo
CVE-2026-118656
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.
Vulnerability class: Open Redirect
Published .
CVSS v3 metric
CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
- Labstack Echo — versions < 4.16.0, >= 5.0.0, < 5.4.0
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-118656?
- CVE-2026-118656 is a medium-severity vulnerability in Labstack Echo, classified under URL Redirection to Untrusted Site (Open Redirect). CVSS score: 6.1/10. Published 2026-10-28.
- How severe is CVE-2026-118656?
- Medium severity. CVSS v3 base score is 6.1 out of 10.