CVE-2026-93861

Severity: medium (CVSS 6.0 v4.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-10-08 · updated 2026-10-15
Weakness: CWE-863

Description

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.

Affected products

OpenStack Mistral: before 20.1.1; from 21.0.0 before 21.0.1; from 22.0.0 before 22.0.1; 23.0.0 — fixed in 20.1.1, 21.0.1, 22.0.1

How to fix

Upgrade to a fixed version: OpenStack Mistral 20.1.1, 21.0.1, 22.0.1. Check the vendor advisory for mitigations.

References

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