CVE-2026-82427

/// Technical description

Description

A topology's `topology.blobstore.map` lets the submitter choose a local name for each blob that the

supervisor localises. That name was used to build a path under the topology's working directory without

normalisation, in both `AsyncLocalizer` and `Container.createBlobstoreLinks`, and the symlink helper

force-deletes whatever already exists at the target before creating the link.

A submitter could therefore use `../` segments to direct that delete-and-symlink operation at an arbitrary

path, as the supervisor user, on every node the topology is scheduled onto. The consequences include

recursive deletion of supervisor-owned content and planting a symlink that causes a subsequent worker

launch to execute attacker-chosen code as another tenant's operating-system user, which defeats the

isolation that `supervisor.run.worker.as.user` is intended to provide.

Mitigation

Upgrade to 3.1.0, where the resolved target must lie inside the expected root at both call sites.

Users who

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References