linuxfabrik-lib: fetch() forwards credential headers across a cross-origin redirect

Exploitation

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

CVSS 4.0

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

EPSS

• CVE-2026-67435: 0.50% estimated exploitation activity in the next 30 days; percentile 42.69 (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 lib.url.fetch() follows HTTP redirects (followredirects=True). httpx strips only Authorization and Cookie when a redirect crosses the origin, so any other caller-supplied credential header (a session token such as Redfish's X-Auth-Token, an API key, ...) was still sent to the redirect target. A malicious or redirect-capable server can therefore answer an authenticated request with a 3xx to an attacker-chosen host and receive the credential (server-side request forgery + token disclosure). The pre-httpx urllib implementation was worse: it forwarded every header, including Authorization, across cross-host redirects. Impact Any plugin that authenticates to a host with a non-standard auth header and follows that host's redirects can be coerced into sending the credential, and an authenticated request, to another host the monitoring server can reach. The concrete case is the Redfish checks (X-Auth-Token), but the flaw is in the shared fetch() and affects every consumer. Patches…

Published by the source

30 Jul 2026, 14:46 UTC

Last modified by the source

30 Jul 2026, 14:46 UTC

Source last checked

26 Oct 2026, 13:50 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-4jc5-g844-4x33

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# Patch Next advisory brief: CVE-2026-67435

Advisory: linuxfabrik-lib: fetch() forwards credential headers across a cross-origin redirect
IDs: CVE-2026-67435, GHSA-4jc5-g844-4x33
Record: https://patchnext.com/advisories/cve-2026-67435 (revision 1, source checked 26 Oct 2026, 13:50 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.0)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: linuxfabrik-lib 6.0.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI linuxfabrik-lib: affected < 6.0.0; fixed in 6.0.0

## Suggested inspection (read-only)
- `python -m pip show linuxfabrik-lib`: prints the installed version. Run with the environment that serves production active.

## 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 linuxfabrik-lib.
- 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-4jc5-g844-4x33 (GitHub-reviewed advisory GHSA-4jc5-g844-4x33 lists affected ranges: PyPI linuxfabrik-lib >=0 <6.0.0)

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