Auth bypass in Nextcloud Flow
CVE-2026-22683
Windmill versions 1.56.0 through 1.614.0 contain a missing authorization vulnerability that allows users with the Operator role to perform prohibited entity creation and modification actions via the backend API. Although Operators are documented and priced as unable to create or modify entities, the API does not enforce the Operator restriction on workspace endpoints, allowing an Operator to create and update scripts, flows, apps, and raw_apps. Since Operators can also execute scripts via the jobs API, this allows direct privilege escalation to remote code execution within the Windmill deployment. This vulnerability has existed since the introduction of the Operator role in version 1.56.0.
Vulnerability class: Broken Access Control
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.026 (84.8th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 85th percentile — 84.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.026 · newest: 0.026 · change: 0.000
Affected products
- Nextcloud Flow — versions 1.0.0
- Windmill
- Windmill Labs Ce (Community Edition) — versions 1.56.0, 1.615.0
- Windmill Labs Ee (Enterprise Edition) — versions 1.56.0, 1.615.0
Weakness classification (CWE)
References
- chocapikk.com/posts/2026/windfall-nextcloud-flow-windmill-rce/ (technical-description, exploit, Vendor Advisory)
- github.com/Chocapikk/Windfall (Product, exploit)
- github.com/windmill-labs/windmill/releases/tag/v1.615.0 (release-notes, Release Notes)
- github.com/windmill-labs/windmill/commit/c621a74804f4f6e8318819c01e3a23a1769858… (Patch, patch)
- www.windmill.dev/ (Product, product)
- apps.nextcloud.com/apps/flow/releases (release-notes, Release Notes)
Frequently asked questions
- What is CVE-2026-22683?
- CVE-2026-22683 is a high-severity vulnerability in Nextcloud Flow, classified under Missing Authorization. CVSS score: 8.8/10. Published 2026-04-07.
- How severe is CVE-2026-22683?
- High severity. CVSS v3 base score is 8.8 out of 10.