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.
{
"cna_assigner": "GitHub_M",
"cwe_ids": [
"CWE-639"
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/105xxx/CVE-2026-105633.json"
}{
"extracted_events": [
{
"range": [
{
"introduced": "0"
},
{
"fixed": "1.4.0"
}
],
"source": "AFFECTED_FIELD",
"strategy": "StringRangeExpression"
},
{
"range": [
{
"fixed": "5829f0febf0739494d576b60d4943d10d236bc96"
}
],
"source": "REFERENCES_COMMIT"
},
{
"original_tag": "v1.4.0",
"range": [
{
"fixed": "917b23a6c16d93fc00cef67900eff2755e8b13f7"
}
],
"source": "REFERENCES_TAG"
}
]
}