CVE-2026-93861: [OSSA-2026-044] OpenStack Mistral: Four authorization and privilege vulnerabilities in Mistral (CVE-2026-93858, CVE-2026-93860, CVE-2026-93861, CVE-2026-97147))
In OpenStack Mistral through 23.0.0, the workflow membership API lets a project that has accepted a share of another project's private workflow create a further membership naming a third project. The new membership row is created with its projectid defaulted to the accepting project rather than the original workflow owner, and thus the owner can neither see nor delete it. The third project can accept this membership (that it had not actually been granted by the owner), and then read and execute the owner's private workflow; only the accepting (not the owning) project can later revoke that access.
Affected Software
Event History
Frequently Asked Questions
Who can exploit this issue?
A project must first have accepted a share of another project's private workflow. That accepting project can create a further membership for a third project, which can then accept it and gain access to read and execute the original owner's private workflow.
Which versions are affected?
The issue affects OpenStack Mistral through version 23.0.0.
Can the workflow owner revoke unauthorized access?
No. The newly created membership is associated with the accepting project rather than the original workflow owner, so the owner cannot see or delete it. Only the accepting intermediary project can later revoke the third project's access.