CAPM3 vulnerable to Cross-Namespace resource access

Exploitation

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

CVSS

5.5 · CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:L/A:N

EPSS

No dated EPSS signal available.

As published by the source; long descriptions are shortened.

Summary CAPM3 is Metal3's Cluster API (CAPI) provider for baremetal provisioning in Kubernetes. Multiple cross-namespace access control vulnerabilities in Cluster API Provider Metal3 allow users with permissions to create or modify CAPM3 resources in one namespace to reference, read, or claim resources belonging to other namespaces. Patched In - v1.13.0 (main branch — all fixes included) - v1.12.5 (all four fixes backported) - v1.11.8 (three of four fixes backported; Metal3DataClaim template restriction not applicable due to missing v1beta2 webhook infrastructure) Description Four related vulnerabilities were identified and fixed: 1. Cross-namespace Secret references in Metal3Machine Metal3Machine resources accepted userData, metaData, and networkData secret references pointing to arbitrary namespaces. A user could configure a Metal3Machine to reference secrets in namespaces they do not have access to, and the controller would fetch and use those secrets. 2. Cross-namespace…

Published by the source

29 May 2026, 19:01 UTC

Last modified by the source

29 May 2026, 19:01 UTC

Source last checked

26 Oct 2026, 15:23 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-rf84-wr5g-m3rp

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# Patch Next advisory brief: GHSA-rf84-wr5g-m3rp

Advisory: CAPM3 vulnerable to Cross-Namespace resource access
IDs: GHSA-rf84-wr5g-m3rp
Record: https://patchnext.com/advisories/ghsa-rf84-wr5g-m3rp (revision 1, source checked 26 Oct 2026, 15:23 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/metal3-io/cluster-api-provider-metal3 1.12.5, 1.11.8. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/metal3-io/cluster-api-provider-metal3: affected <= 1.11.7; >= 1.12.0, <= 1.12.4; fixed in 1.11.8, 1.12.5

## Suggested inspection (read-only)
- Go github.com/metal3-io/cluster-api-provider-metal3: 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/metal3-io/cluster-api-provider-metal3.
- 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-rf84-wr5g-m3rp (GitHub-reviewed advisory GHSA-rf84-wr5g-m3rp lists affected ranges: Go github.com/metal3-io/cluster-api-provider-metal3 >=0 =1.12.0 <=1.12.4)

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