Summary
CVE-2026-57578 is a critical missing-authorization vulnerability (CWE-862) in DotVVM, an open-source MVVM framework for building web applications on ASP.NET. The framework’s AuthorizeActionFilter fails to perform any authorization checks, allowing unauthenticated network attackers to invoke protected commands, view models, and presenters without bypass techniques. The issue carries a CVSS v3.1-equivalent severity of 9.2 (Critical).
Technical details
- Root cause:
AuthorizeActionFilter‘s implementations ofICommandActionFilter.OnCommandExecutingAsync,IViewModelActionFilter.OnViewModelCreatedAsync, andIPresenterActionFilter.OnPresenterExecutingAsyncreturn already-completed tasks instead of executing the intended authorization logic. - Trigger conditions: Any DotVVM application that relies on
AuthorizeActionFilterto protect commands, view models, or presenters is affected — the filter never actually enforces access control. - Attack vector: Network-based; no authentication, user interaction, or special exploitation technique is required to reach protected functionality.
- Impact: Complete bypass of authorization controls on affected commands/view models/presenters, exposing them to unauthorized read and write access.
Affected software
- DotVVM versions prior to 4.2.11
- DotVVM versions 4.3.0 through 4.3.14
- DotVVM 5.0.0 preview versions preview01 through preview08
Severity
- CVSS Score: 9.2 (Critical)
- Note: The vendor advisory publishes this score under CVSS v4.0 (AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N).
Mitigation and recommended actions
- Immediate: Upgrade DotVVM to version 4.2.11, 4.3.15, or 5.0.0-preview09-final (or later), depending on the branch in use.
- If no patch can be applied immediately: Replace usage of
AuthorizeActionFilterwith theAuthorizeAttribute, which correctly implements the same authorization interfaces, as an interim workaround.

