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GHSA-q6hv-wcjr-wp8h

kcp is missing update validation allows arbitrary LogicalCluster status patches through initializingworkspaces Virtual Workspace

Also known asGO-2025-3985
Published
Sep 26, 2025
Updated
Oct 23, 2025
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed

Blast Radius

1 pkg affected
🐹github.com/kcp-dev/kcp

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.

Description

Impact

Because UPDATE validation is not being applied, it is possible for an actor with access to an instance of the initializingworkspaces virtual workspace to run arbitrary patches on the status field of LogicalCluster objects while the workspace is initializing.

This allows to add or remove any initializers as well as changing the phase of a LogicalCluster (to "Ready" for example).

As this effectively allows to skip certain initializers or the entire initialization phase, potential integrations with external systems such as billing or security could be affected. Their initializers could be skipped by a WorkspaceType that adds another initializer and grants permissions to the virtual workspace to a rogue or compromised entity.

Who is impacted?

  • Impacts other owners of WorkspaceTypes with initializers that are inherited by other WorkspaceTypes.
  • Impacts developers using the virtual/framework package to create their own virtualworkspaces if they are using UpdateFuncs in their custom storageWrappers.

Details

The issue occurs because the rest.ValidateObjectUpdateFunc is not being called within the DefaultDynamicDelegatedStoreFuncs. As a result, the intended status overwrite protection from initializers never gets called, allowing arbitrary logicalcluster status patches.

Patches

The problem has been patched in #3599 and is available in kcp 0.28.3 and higher.

Workarounds

  • Further limit access to the initialize verb on WorkspaceType objects (see documentation for details).
  • Only use trusted WorkspaceType objects.

References

See the pull request (#3599).

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
🐹Gogithub.com/kcp-dev/kcpall versions0.28.3

Detection & mitigation playbook

Open-source dependency
  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/kcp-dev/kcp. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

  2. Fix

    Update github.com/kcp-dev/kcp to 0.28.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-q6hv-wcjr-wp8h is resolved across your whole dependency graph.

  3. Workarounds

    If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

  4. How O3 protects you

    O3 pinpoints whether GHSA-q6hv-wcjr-wp8h is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to GHSA-q6hv-wcjr-wp8h. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

### Impact Because UPDATE validation is not being applied, it is possible for an actor with access to an instance of the [initializingworkspaces virtual workspace](https://docs.kcp.io/kcp/latest/concepts/workspaces/workspace-initialization/) to run arbitrary patches on the status field of `LogicalCluster` objects while the workspace is initializing. This allows to add or remove any initializers as well as changing the phase of a `LogicalCluster` (to "Ready" for example). As this effectively allows to skip certain initializers or the entire initialization phase, potential integrations with e
O3 Security · Impact-Aware SCA

Is GHSA-q6hv-wcjr-wp8h in your dependencies?

O3 detects GHSA-q6hv-wcjr-wp8h across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.