CVE-2026-67435 — linuxfabrik-lib
Fix: Linuxfabrik/lib@6573ff9CVE-2026-67435 is a Information Exposure vulnerability in linuxfabrik-lib. A fix is available for linuxfabrik-lib — see the affected versions and patch details below.
linuxfabrik-lib: fetch() forwards credential headers across a cross-origin redirect
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-67435.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
Real-World Exposure
linuxfabrik-libReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
Summary
lib.url.fetch() follows HTTP redirects (follow_redirects=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
Fixed in linuxfabrik-lib 6.0.0 (commit 6573ff9). On a cross-origin redirect (any scheme/host/port change other than a plain same-host HTTP-to-HTTPS upgrade) fetch() now keeps only benign transport headers and drops every other caller-supplied header, so credentials never follow a redirect to a different origin.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | linuxfabrik-lib | all versions | 6.0.0pip install --upgrade 'linuxfabrik-lib==6.0.0' |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for linuxfabrik-lib, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update linuxfabrik-lib to 6.0.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-67435 is resolved across your whole dependency graph.
Workarounds
Restrict outbound requests from the affected component to an allowlist of hosts, block access to link-local and internal address ranges at the network layer, and require authentication on internal services so a forged request cannot reach them unauthenticated.
Frequently Asked Questions
Is CVE-2026-67435 in your dependencies?
Find it across PyPI, including transitive dependencies.