What is the CVSS score of CVE-2026-46558?

CVE-2026-46558 has a CVSS 3.1 base score of 8.3 (High). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L. EPSS exploitation probability: 0.0%.

Which versions of Plane are affected by CVE-2026-46558?

Plane prior to v1.3.1 fails to enforce workspace isolation, allowing authenticated users to access and modify files across all workspaces on a shared instance.. A patch is available.

Is there a public PoC exploit available for CVE-2026-46558?

Yes, a public proof-of-concept exploit is available for CVE-2026-46558. Prioritise patching immediately. EPSS: 0.0%.

How to fix or mitigate CVE-2026-46558?

24 hours: Determine Plane version and whether multi-workspace deployments are in use; audit recent access logs for suspicious cross-workspace API activity. 7 days: Test and validate Plane v1.3.1 in staging environment. 30 days: Deploy v1.3.1 to all production Plane instances and verify updated version.

Plane CVE-2026-46558

EUVD-2026-36066 HIGH

Authorization Bypass Through User-Controlled Key (CWE-639)

2026-06-10 GitHub_M

Authentication Bypass Plane Makeplane

8.3

CVSS 3.1 · Vendor: GitHub_M

Severity by source

Vendor (GitHub_M) PRIMARY

8.3 HIGH

AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L

Primary rating from Vendor (GitHub_M) · only source for this CVE.

CVSS VectorVendor: GitHub_M

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

Low

Lifecycle Timeline

Patch available

Jun 10, 2026 - 17:01 EUVD

Source Code Evidence Fetched

Jun 10, 2026 - 16:21 vuln.today

Analysis Generated

Jun 10, 2026 - 16:21 vuln.today

DescriptionCVE.org

Plane is an open-source project management tool. Prior to version 1.3.1, there is a cross-workspace asset authorization bypass lets any authenticated user read, copy, delete, and overwrite assets in other Plane workspaces. This issue has been patched in version 1.3.1.

AnalysisAI

Cross-workspace authorization bypass in Plane (makeplane) prior to version 1.3.1 allows any authenticated user of one workspace to read, copy, delete, and overwrite file assets belonging to other workspaces on the same instance. The flaw stems from missing membership checks on V2 asset endpoints and is fixed in v1.3.1; no public exploit identified at time of analysis.

Technical ContextAI

Plane is an open-source project management platform (cpe:2.3:a:makeplane:plane) that segregates data by workspace. The vulnerability is classified as CWE-639 (Authorization Bypass Through User-Controlled Key), a classic IDOR pattern. According to the v1.3.1 release notes, the root cause was that the WorkspaceFileAssetEndpoint methods lacked the @allow_permission decorator, and the DuplicateAssetEndpoint did not scope its source-asset lookup to workspaces where the requester was an active member. As a result, asset object IDs (likely UUIDs or similar identifiers passed in API paths) were trusted without verifying that the caller belonged to the workspace owning the asset, enabling cross-tenant access on shared/multi-tenant Plane deployments.

RemediationAI

Vendor-released patch: Plane v1.3.1, available at https://github.com/makeplane/plane/releases/tag/v1.3.1, with details in GHSA-qw87-v5w3-6vxx (https://github.com/makeplane/plane/security/advisories/GHSA-qw87-v5w3-6vxx); upgrade is the primary and recommended remediation as it adds @allow_permission to all WorkspaceFileAssetEndpoint methods and scopes DuplicateAssetEndpoint's source-asset lookup to workspaces where the caller is an active member. If immediate upgrade is not possible on a multi-tenant instance, restrict the V2 asset and duplicate-asset endpoints (e.g., the /workspaces/.../file-assets/ and duplicate routes) at a reverse proxy to a trusted subset of users, or temporarily run separate single-tenant Plane instances per workspace; both controls degrade collaboration features (file uploads/downloads and asset duplication) and do not stop a malicious tenant who retains endpoint access, so they should be treated as stopgaps until v1.3.1 is deployed. Rotating or auditing existing asset URLs after upgrade is advisable since previously leaked asset identifiers could still be referenced.