---
id: CVE-2026-93861
title: >-
  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
summary: >-
  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 it…
severity: medium
cvss: 6
cvssVector: 'CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N'
cwe:
  - CWE-863
vendor: OpenStack
product: Mistral
affected:
  - Mistral < 20.1.1
  - Mistral >= 21.0.0 < 21.0.1
  - Mistral >= 22.0.0 < 22.0.1
  - Mistral 23.0.0
published: '2026-10-08'
updated: '2026-10-08'
sourceUpdated: '2026-10-08T21:10:41.427'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-93861'
references:
  - url: 'https://launchpad.net/bugs/2161277'
    label: cve@mitre.org
  - url: 'https://security.openstack.org/ossa/OSSA-2026-044.html'
    label: cve@mitre.org
tags:
  - nvd
  - cve.org
cvssSource: cna
ingestedAt: '2026-10-08T17:56:11.731Z'
---

## Overview

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 project_id 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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.