# CVE-2026-118658: Echo: Arbitrary Scheme Injection in WWWRedirect/NonWWWRedirect Middlewares via X-Forwarded-Proto

Status: published. Published: 2026-10-28. Updated: 2026-11-02.

Echo is a Go web framework. Prior to 4.15.2 and 5.1.1, Context.Scheme returns values from X-Forwarded-Proto, X-Forwarded-Protocol, or X-Url-Scheme without validating that they are supported web schemes. WWWRedirect and NonWWWRedirect use that value to construct a Location header, so an attacker controlling a forwarded scheme header can cause a redirect to use an arbitrary URI scheme. Exploitation requires an affected redirect middleware and user interaction with the response; the HTTPS-specific redirect variants hardcode HTTPS and are unaffected. This issue is fixed in 4.15.2 and 5.1.1.

## Remediation

- fix: github.com/labstack/echo/v5 (Go): OSV reports a fixed version 5.1.1. Check the advisory for supported release branches. (source: OSV GHSA-23wf-92cp-8pcj) — https://github.com/advisories/GHSA-23wf-92cp-8pcj
- fix: github.com/labstack/echo/v4 (Go): OSV reports a fixed version 4.15.2. Check the advisory for supported release branches. (source: OSV GHSA-23wf-92cp-8pcj) — https://github.com/advisories/GHSA-23wf-92cp-8pcj

## Affected products and versions

- labstack / echo: >= 5.0.0, < 5.1.1 (affected); < 4.15.2 (affected). Source: CNA: GitHub_M
-  / github.com/labstack/echo/v5 (github.com/labstack/echo/v5): ≥ 0; < 5.1.1 (affected, semver); OSV events: introduced 0; fixed 5.1.1. Source: OSV GHSA-23wf-92cp-8pcj
-  / github.com/labstack/echo/v4 (github.com/labstack/echo/v4): ≥ 0; < 4.15.2 (affected, semver); OSV events: introduced 0; fixed 4.15.2. Source: OSV GHSA-23wf-92cp-8pcj

## Severity and prioritization

- CVSS 3.1: 4.7 (medium); CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N; source: CNA: GitHub_M

- CISA KEV: No listing in collected sources

- EPSS: 0.19% as of 2026-11-02; percentile 8.17%

- SSVC: exploitation poc; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-601

## Exploit evidence

- exploit: https://github.com/labstack/echo/security/advisories/GHSA-23wf-92cp-8pcj (ADP: CISA-ADP)

## References

- https://github.com/labstack/echo/security/advisories/GHSA-23wf-92cp-8pcj (CNA: GitHub_M; x_refsource_CONFIRM)

- https://github.com/labstack/echo/commit/ca4f38a474302aabee93c66bdd0052359882e181 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/labstack/echo/commit/d1d8ad3f99dd9b80542cd0c357d56a8916c515df (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/labstack/echo/releases/tag/v4.15.2 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/labstack/echo/releases/tag/v5.1.1 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/labstack/echo/security/advisories/GHSA-23wf-92cp-8pcj (ADP: CISA-ADP; exploit)

- https://github.com/advisories/GHSA-23wf-92cp-8pcj (OSV / GitHub Security Advisories; advisory)

- https://osv.dev/vulnerability/GHSA-23wf-92cp-8pcj (OSV / GitHub Security Advisories; osv)

## Provenance

- CNA: GitHub_M: https://www.cve.org/CVERecord?id=CVE-2026-118658; retrieved 2026-11-02; source updated 2026-11-02

- OSV / GitHub Security Advisories: https://osv.dev/vulnerability/GHSA-23wf-92cp-8pcj; retrieved 2026-11-02; source updated 2026-10-28

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-118658; retrieved 2026-11-02; source updated Not reported

Revision: 24502cb9d788a62ed347d65b7a9b0b7a8e56729af560a55eea28ba1873183fef

Canonical: https://y2.dev/cve/CVE-2026-118658

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