Authorization bypass in Plane lets members take attachment ownership
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- None · High · Low
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-639.
Summary
Plane before 1.4.0 has an authorization bypass in its V2 issue-attachment PATCH endpoint. The endpoint ignores the issue_id in the URL when it looks up an attachment, so a project member can modify another user's pending attachment by its UUID. The handler then transfers the attachment's ownership to the attacker (CWE-639). An attacker needs a low-privileged project member account and can reach the endpoint over the network, and the flaw affects integrity and availability.
Written with Claude Haiku 5.5 from the sources below · 2026-10-29
Description from the CNA
Plane is an open-source project management tool. Prior to 1.4.0, the V2 issue-attachment PATCH endpoint accepts issue_id in the URL but omits it from the database query. A project member can use an issue_id they control in the URL while targeting another user's attachment by its pk UUID. Because the server matches only pk, workspace, and project_id, it modifies the attachment regardless of the issue_id in the URL. When the attachment is pending and has not been confirmed as uploaded, the PATCH handler sets created_by = request.user and transfers attachment ownership to the attacker. This issue is fixed in 1.4.0.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
Upgrade Plane to version 1.4.0, which fixes this issue.
Written with Claude Haiku 5.5 from the sources below · 2026-10-29
- Fix · CNA plane (makeplane) Fixed in 1.4.0
Timeline
- 2026-10-05 Threatist record created from CVE-2026-105633
References
More makeplane vulnerabilities
- TI-2026-67866 Hardcoded secret keys in Plane community deployments CVSS 3.1CRITICAL 9.8
- TI-2026-67865 Account takeover in Plane via unverified OAuth email matching CVSS 3.1CRITICAL 9.1
- TI-2026-67863 Plane magic-code login lacks rate limiting, allowing OTP brute force CVSS 3.1CRITICAL 9.1
- TI-2024-32097 Plane allows server side request forgery via /_next/image endpoint CVSS 3.1CRITICAL 9.3
- TI-2026-67862 Cross-project asset hijacking in Plane allows file takeover CVSS 3.1CRITICAL 9.6
- TI-2026-67861 Server-side request forgery in Plane webhook delivery via redirects CVSS 3.1CRITICAL 9.9
Sources
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences