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 docu…
Vulnerability class: Broken Access Control
EPSS: 0.004 (61.1th percentile) — read the EPSS interpretation.
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.
Affected products
- Nextcloud Flow — versions 1.0.0
- 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)
- github.com/Chocapikk/Windfall (exploit)
- github.com/windmill-labs/windmill/releases/tag/v1.615.0 (release-notes)
- github.com/windmill-labs/windmill/commit/c621a74804f4f6e8318819c01e3a23a1769858… (patch)
- www.windmill.dev/ (product)
- apps.nextcloud.com/apps/flow/releases (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.