Vulnerability 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.
CVSS Score
MEDIUM
Related Weaknesses (CWE)
References
- https://github.com/labstack/echo/commit/b838391e2eade87ae7e5a09d7bb5087bec271ec1
- https://github.com/labstack/echo/commit/fc410094b2f3415cf2bf5204082137b205bfd5af
- https://github.com/labstack/echo/releases/tag/v4.16.0
- https://github.com/labstack/echo/releases/tag/v5.4.0
- https://github.com/labstack/echo/security/advisories/GHSA-v753-g4cw-jm48
FAQ
What is CVE-2026-118656?
CVE-2026-118656 is a vulnerability with a CVSS score of 6.1 (MEDIUM). 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 Add...
How severe is CVE-2026-118656?
CVE-2026-118656 has been rated MEDIUM with a CVSS base score of 6.1/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-118656?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.