{"id":"CVE-2026-104970","published":"2026-10-05T17:17:12.937","lastModified":"2026-10-06T15:17:13.220","description":"Plane is an open-source project management tool. From 0.13 until 1.4.0, InstanceAdminSignUpEndpoint in apps/api/plane/license/api/views/admin.py:89-117, 173-229 uses InstanceAdmin.objects.first() for the first-admin check and performs account creation without an atomic transaction, row lock, uniqueness guard, or advisory lock. Two concurrent unauthenticated requests with different email addresses can both observe that no instance administrator exists, create separate User and InstanceAdmin rows, and receive sessions with instance-admin authority. This allows an attacker to share unrestricted instance administration with the legitimate operator. This issue is fixed in 1.4.0.","cvssScore":8.1,"cvssSeverity":"HIGH","cvssVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H","cwes":["CWE-362"],"vendors":[],"products":[],"references":[{"url":"https://github.com/makeplane/plane/commit/7fbf14a6cb494bbf5866e2b293b28a6d8a7e52c3","tags":[]},{"url":"https://github.com/makeplane/plane/pull/9332","tags":[]},{"url":"https://github.com/makeplane/plane/releases/tag/v1.4.0","tags":[]},{"url":"https://github.com/makeplane/plane/security/advisories/GHSA-p548-28jp-wr4p","tags":[]}],"exploitRefs":[{"url":"https://github.com/makeplane/plane/commit/7fbf14a6cb494bbf5866e2b293b28a6d8a7e52c3","tags":[]},{"url":"https://github.com/makeplane/plane/pull/9332","tags":[]},{"url":"https://github.com/makeplane/plane/releases/tag/v1.4.0","tags":[]},{"url":"https://github.com/makeplane/plane/security/advisories/GHSA-p548-28jp-wr4p","tags":[]}],"hasPoc":true,"ai":{"summary":"The flaw allows two unauthenticated users to create separate admin accounts, granting both unrestricted instance administration, due to the lack of transactional and locking mechanisms.","exploitability":"Exploitation is moderately hard as it requires two concurrent unauthenticated requests, but preconditions are minimal.","blast_radius":"If exploited, this could lead to unauthorized access and control over the entire project management instance, severely impacting data integrity and security.","remediation":"Upgrade to version 1.4.0 or later.","detection":"No reliable host or network indicator is derivable from the published description.","tags":["auth-bypass","web","misconfiguration"],"model":"qwen2.5:7b-instruct","analyzedAt":"2026-10-06T08:45:33.994Z"}}