Echo has Arbitrary Scheme Injection in WWWRedirect/NonWWWRedirect Middlewares via X-Forwarded-Proto

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

4.7 · CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N

EPSS

• CVE-2026-118658: 0.19% estimated exploitation activity in the next 30 days; percentile 8.23 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary The c.Scheme() method in Echo (context.go:162-181) trusts the X-Forwarded-Proto, X-Forwarded-Protocol, and X-Url-Scheme request headers without validating that the value is http or https. The WWWRedirect() and NonWWWRedirect() middlewares use this unsanitized scheme to construct redirect URLs, allowing an attacker to inject arbitrary URI schemes into the Location response header. Affected Components - context.go:162-181 - Scheme() method returns attacker-controlled value verbatim - middleware/redirect.go:172-184 - redirectWWW/redirectNonWWW use unsanitized scheme Proof of Concept Confirmed injectable schemes: javascript, data, vbscript, file, ftp, ssh, telnet, gopher. Only WWWRedirect() and NonWWWRedirect() (and WithConfig variants) are affected. HTTPSRedirect, HTTPSWWWRedirect, HTTPSNonWWWRedirect are NOT affected (they hardcode https://). Impact - Open redirect to arbitrary scheme URLs when app is not behind a proxy that strips X-Forwarded-Proto - Cache poisoning when…

Published by the source

28 Oct 2026, 21:04 UTC

Last modified by the source

31 Oct 2026, 12:39 UTC

Source last checked

31 Oct 2026, 13:15 UTC

1. Revision 3 · amended · 31 Oct 2026

   Amended from ghsa record GHSA-23wf-92cp-8pcj

2. Revision 2 · amended · 29 Oct 2026

   Amended from osv record GHSA-23wf-92cp-8pcj

3. Revision 1 · created · 28 Oct 2026

   Published from ghsa record GHSA-23wf-92cp-8pcj

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# Patch Next advisory brief: CVE-2026-118658

Advisory: Echo has Arbitrary Scheme Injection in WWWRedirect/NonWWWRedirect Middlewares via X-Forwarded-Proto
IDs: CVE-2026-118658, GHSA-23wf-92cp-8pcj
Record: https://patchnext.com/advisories/cve-2026-118658 (revision 3, source checked 31 Oct 2026, 13:15 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 4.7)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/labstack/echo/v4 4.15.2; github.com/labstack/echo/v5 5.1.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/labstack/echo/v4: affected < 4.15.2; fixed in 4.15.2
- Go github.com/labstack/echo/v5: affected < 5.1.1; fixed in 5.1.1

## Suggested inspection (read-only)
- Go github.com/labstack/echo/v4: check the installed version with your package manager.
- Go github.com/labstack/echo/v5: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/labstack/echo/v4, github.com/labstack/echo/v5.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-23wf-92cp-8pcj (GitHub-reviewed advisory GHSA-23wf-92cp-8pcj lists affected ranges: Go github.com/labstack/echo/v5 >=0 =0 <4.15.2)
- Verified: https://osv.dev/vulnerability/GHSA-23wf-92cp-8pcj (OSV record GHSA-23wf-92cp-8pcj lists affected ranges: Go github.com/labstack/echo/v5 >=0 =0 <4.15.2 (fixed))

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