CVE-2026-22683

HighUpdated

Published: 07 April 2026

Published

07 April 2026

Modified

24 April 2026

KEV Added

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Patch

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CVSS Score 8.8 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Score 0.0040 61.0th percentile

Risk Priority 18 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-22683 is a high-severity Missing Authorization (CWE-862) vulnerability in Nextcloud Flow. Its CVSS base score is 8.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 39.0% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified are NIST 800-53 AC-3 (Access Enforcement) and AC-6 (Least Privilege).

Threat & Defense at a Glance

What attackers do: exploitation maps to Exploit Public-Facing Application (T1190) and 1 other technique. What defenders deploy: see the NIST 800-53 controls recommended below.

Threat & Defense Details

Mitigating Controls (NIST 800-53 r5)AI

AC-3 Access Enforcement good match

prevent

Directly mandates enforcement of approved authorizations, addressing the missing API restrictions that allow Operators to create and modify workspace entities.

AC-6 Least Privilege good match

prevent

Enforces least privilege principle to restrict Operators from unauthorized entity creation, modification, and subsequent RCE via jobs API.

AC-24 Access Control Decisions partial match

prevent

Requires access control decisions to correctly deny Operator role actions on workspace endpoints per policy.

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access

Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.

attack.mitre.org →

T1068 Exploitation for Privilege Escalation Privilege Escalation

Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.

attack.mitre.org →

Why these techniques?

Missing authorization in Windmill API enables low-privileged Operator role to create/update/execute scripts for RCE, directly facilitating exploitation of a public-facing application (T1190) and exploitation for privilege escalation (T1068).

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

NVD Description

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.

Deeper analysisAI

CVE-2026-22683 is a missing authorization vulnerability (CWE-862) affecting Windmill versions 1.56.0 through 1.614.0. The flaw arises because the backend API fails to enforce restrictions on the Operator role for workspace endpoints, despite documentation stating that Operators cannot create or modify entities. This allows Operators to create and update scripts, flows, apps, and raw_apps. The vulnerability has existed since the Operator role's introduction in version 1.56.0 and carries a CVSS v3.1 base score of 8.8 (AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H).

An authenticated user with the Operator role can exploit this vulnerability over the network with low complexity and no user interaction. By leveraging the unenforced API endpoints, the attacker can create or modify arbitrary entities such as scripts and then execute them via the jobs API. This chain enables direct privilege escalation to remote code execution within the Windmill deployment.

Mitigation is available in Windmill version 1.615.0, as indicated by the project's release notes and a specific commit (c621a74804f4f6e8318819c01e3a23a17698588b) that addresses the authorization bypass. Security practitioners should upgrade to v1.615.0 or later and review Operator role assignments.

A public proof-of-concept exploit named Windfall is available on GitHub (Chocapikk/Windfall), with related details in a blog post detailing remote code execution via Windmill in the context of Nextcloud Flow.