# CVE-2026-104964: Plane: Cross-Workspace Project Modification via Unscoped Project Lookup

> An administrator in one workspace can modify projects in another workspace by exploiting unscoped project lookups, violating tenant isolation.

- **Severity:** Medium 6.8 (`CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:N/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 5 Oct 2026
- **Updated:** 5 Oct 2026
- **Also known as:** GHSA-pp22-3ghf-949q

## What is CVE-2026-104964?

CVE-2026-104964 is a medium-severity missing authorization vulnerability in makeplane plane, published on 5 Oct 2026. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

Plane is an open-source project management tool. Prior to 1.4.0, Plane's project update endpoint authorizes the caller against the workspace slug in the request URL but loads the target project globally by UUID without binding it to that workspace. An administrator of one workspace can modify a project in another workspace when the victim project UUID is known. This violates tenant isolation and permits unauthorized cross-workspace changes to project metadata and configuration. This issue is fixed in 1.4.0.

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

## Which versions are affected by CVE-2026-104964?


## How do I fix CVE-2026-104964?

No fix has been published for CVE-2026-104964 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-104964 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-104964 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-104964 and fix it if it is affected.

What it is: CVE-2026-104964 is a medium-severity missing authorization vulnerability in makeplane plane, published on 5 Oct 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-104964 exists.

Affected product: makeplane plane. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-104964/ (Markdown: https://insights.sbomify.com/CVE-2026-104964/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-104964
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-104964
- OSV: https://osv.dev/vulnerability/CVE-2026-104964

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-104964/
Summaries are generated and may contain mistakes; the official description above is the record.