Hubuum client library (Rust): Configured custom transports may be bypassed, exposing credentials and network traffic

Exploitation

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

CVSS 4.0

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

EPSS

No dated EPSS signal available.

As published by the source; long descriptions are shortened.

Summary When an application configures hubuumclient with ClientBuilder::withtransport, several client operations still use the built-in reqwest client directly. The bypass includes password login, bearer-token validation, authentication-provider discovery, health and readiness probes, export-output downloads, and unified-search streams. Impact Applications may use a custom transport as a security boundary for network isolation, proxy enforcement, request signing, audit logging, or policy checks. Affected operations bypass those controls and make direct network requests to the configured base URL. Password login can therefore send plaintext credentials outside the intended transport, while token validation can send a bearer token outside it. Other bypassing calls can evade audit and routing policy. The issue affects custom transports introduced in 0.3.0. Applications that do not configure a custom transport are not affected by the bypass. Defense in depth The same private fix disables…

Published by the source

24 Jul 2026, 21:49 UTC

Last modified by the source

24 Jul 2026, 21:49 UTC

Source last checked

26 Oct 2026, 15:43 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-qqc3-94qv-7fw3

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# Patch Next advisory brief: GHSA-qqc3-94qv-7fw3

Advisory: Hubuum client library (Rust): Configured custom transports may be bypassed, exposing credentials and network traffic
IDs: GHSA-qqc3-94qv-7fw3
Record: https://patchnext.com/advisories/ghsa-qqc3-94qv-7fw3 (revision 1, source checked 26 Oct 2026, 15:43 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: hubuum_client 0.6.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- crates.io hubuum_client: affected >= 0.3.0, <= 0.6.0; fixed in 0.6.1

## Suggested inspection (read-only)
- crates.io hubuum_client: 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 hubuum_client.
- 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-qqc3-94qv-7fw3 (GitHub-reviewed advisory GHSA-qqc3-94qv-7fw3 lists affected ranges: crates.io hubuum_client >=0.3.0 <=0.6.0)

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