# CVE-2026-118657: Echo: HTTPS Redirect and HSTS Bypass via Unconditional Trust of Forwarded Scheme Headers

Status: published. Published: 2026-10-28. Updated: 2026-11-03.

Echo is a Go web framework. Prior to 4.16.0 and 5.4.0, Context.Scheme unconditionally trusts forwarded scheme headers from any client. A client that reaches Echo directly over plaintext HTTP can claim an HTTPS scheme and bypass HTTPSRedirect because the request is treated as already secure. Separately, behind a TLS-terminating proxy that passes an attacker-controlled header, a claimed HTTP scheme can suppress the Strict-Transport-Security header even though the browser receives the response over HTTPS. The practical risk is reduced when a trusted proxy overwrites the headers and direct backend access is prevented, but the framework previously had no trusted-source configuration for this decision. This issue is fixed in 4.16.0 and 5.4.0.

## Remediation

- fix: github.com/labstack/echo/v5 (Go): OSV reports a fixed version 5.4.0. Check the advisory for supported release branches. (source: OSV GHSA-2ffq-g2xg-c22p) — https://github.com/advisories/GHSA-2ffq-g2xg-c22p
- fix: github.com/labstack/echo/v4 (Go): OSV reports a fixed version 4.16.0. Check the advisory for supported release branches. (source: OSV GHSA-2ffq-g2xg-c22p) — https://github.com/advisories/GHSA-2ffq-g2xg-c22p

## Affected products and versions

- labstack / echo: >= 5.0.0, < 5.4.0 (affected); < 4.16.0 (affected). Source: CNA: GitHub_M
-  / github.com/labstack/echo/v5 (github.com/labstack/echo/v5): ≥ 0; < 5.4.0 (affected, semver); OSV events: introduced 0; fixed 5.4.0. Source: OSV GHSA-2ffq-g2xg-c22p
-  / github.com/labstack/echo/v4 (github.com/labstack/echo/v4): ≥ 0; < 4.16.0 (affected, semver); OSV events: introduced 0; fixed 4.16.0. Source: OSV GHSA-2ffq-g2xg-c22p

## Severity and prioritization

- CVSS 3.1: 5.9 (medium); CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:L/A:N; source: CNA: GitHub_M

- CISA KEV: No listing in collected sources

- EPSS: 0.13% as of 2026-11-02; percentile 2.83%

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

- Weaknesses: CWE-346

## Exploit evidence

- exploit: https://github.com/labstack/echo/security/advisories/GHSA-2ffq-g2xg-c22p (ADP: CISA-ADP)

## References

- https://github.com/labstack/echo/security/advisories/GHSA-2ffq-g2xg-c22p (CNA: GitHub_M; x_refsource_CONFIRM)

- https://github.com/labstack/echo/commit/b838391e2eade87ae7e5a09d7bb5087bec271ec1 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/labstack/echo/commit/fc410094b2f3415cf2bf5204082137b205bfd5af (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/labstack/echo/releases/tag/v4.16.0 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/labstack/echo/releases/tag/v5.4.0 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/labstack/echo/security/advisories/GHSA-2ffq-g2xg-c22p (ADP: CISA-ADP; exploit)

- https://github.com/advisories/GHSA-2ffq-g2xg-c22p (OSV / GitHub Security Advisories; advisory)

- https://osv.dev/vulnerability/GHSA-2ffq-g2xg-c22p (OSV / GitHub Security Advisories; osv)

## Provenance

- CNA: GitHub_M: https://www.cve.org/CVERecord?id=CVE-2026-118657; retrieved 2026-11-03; source updated 2026-11-03

- OSV / GitHub Security Advisories: https://osv.dev/vulnerability/GHSA-2ffq-g2xg-c22p; retrieved 2026-11-03; source updated 2026-10-28

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-118657; retrieved 2026-11-03; source updated Not reported

Revision: 6753e1baf9a1c41cf6d3b289e537cb86f33cb57262db7ad0bf7eded7950656f9

Canonical: https://y2.dev/cve/CVE-2026-118657

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