chi Allows Host Header Injection which Leads to Open Redirect in RedirectSlashes

Exploitation

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

CVSS 4.0

5.1 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N · score source

EPSS

• CVE-2025-71405: 0.39% estimated exploitation activity in the next 30 days; percentile 33.00 (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 RedirectSlashes function in middleware/strip.go is vulnerable to host header injection which leads to open redirect. We consider this a lower-severity open redirect, as it can't be exploited from browsers or email clients (requires manipulation of a Host header). Details The RedirectSlashes method uses the Host header to construct the redirectURL at this line https://github.com/go-chi/chi/blob/master/middleware/strip.go#L55 The Host header can be manipulated by a user to be any arbitrary host. This leads to open redirect when using the RedirectSlashes middleware PoC Create a simple server which uses the RedirectSlashes middleware Run the server go run main.go Once the server is running, send a request that will trigger the RedirectSlashes function with an arbitrary Host header curl -iL -H "Host: example.com" http://localhost:8080/test/ Observe that the request will be redirected to example.com Without the host header, the response is returned from the test server Impact…

Published by the source

20 Jun 2025, 16:37 UTC

Last modified by the source

2 Oct 2026, 23:17 UTC

Source last checked

26 Oct 2026, 15:29 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-vrw8-fxc6-2r93

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# Patch Next advisory brief: CVE-2025-71405

Advisory: chi Allows Host Header Injection which Leads to Open Redirect in RedirectSlashes
IDs: CVE-2025-71405, GHSA-vrw8-fxc6-2r93
Record: https://patchnext.com/advisories/cve-2025-71405 (revision 1, source checked 26 Oct 2026, 15:29 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.1)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/go-chi/chi/v5 5.2.2. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/go-chi/chi/v5: affected <= 5.2.1; fixed in 5.2.2

## Suggested inspection (read-only)
- Go github.com/go-chi/chi/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/go-chi/chi/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-vrw8-fxc6-2r93 (GitHub-reviewed advisory GHSA-vrw8-fxc6-2r93 lists affected ranges: Go github.com/go-chi/chi/v5 >=0 <=5.2.1)

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