# CVE-2026-104966: Plane: Cross-Workspace IDOR in Estimate and Comment Endpoints Allows Read, Modify, and Inject Across Workspaces

> Authenticated users can read, modify, or inject data across workspaces due to missing scope validation on estimate and comment endpoints.

- **Severity:** High 8.7 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 5 Oct 2026
- **Updated:** 6 Oct 2026
- **Also known as:** GHSA-933r-rxg8-f3h2

## What is CVE-2026-104966?

CVE-2026-104966 is a high-severity missing authorization vulnerability in makeplane plane, published on 5 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Plane is an open-source project management tool. Prior to 1.4.0, two endpoint families fail to verify that nested resource identifiers belong to the workspace and project named in the URL. An authenticated user can read or modify estimates from another workspace through PATCH /api/workspaces/{slug}/projects/{project_id}/estimates/{estimate_id}/, and can inject comments into an issue from another workspace through POST /api/workspaces/{slug}/projects/{project_id}/issues/{issue_id}/comments/. ProjectEntityPermission verifies membership in the workspace and project from the URL, but estimate_id and issue_id are fetched by primary key without confirming the same scope. The list, retrieve, and destroy handlers correctly scope their queries, demonstrating the inconsistency. This issue is fixed in 1.4.0.

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

## Which versions are affected by CVE-2026-104966?


## How do I fix CVE-2026-104966?

No fix has been published for CVE-2026-104966 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-104966 being exploited?

There is no known exploitation of CVE-2026-104966 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-104966 and fix it if it is affected.

What it is: CVE-2026-104966 is a high-severity missing authorization vulnerability in makeplane plane, published on 5 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-104966 in the wild and no public exploit code.

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-2026-104966/ (Markdown: https://insights.sbomify.com/CVE-2026-104966/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-104966
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-104966
- OSV: https://osv.dev/vulnerability/CVE-2026-104966

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-104966/
Summaries are generated and may contain mistakes; the official description above is the record.