CVE-2026-57577

Description

DotVVM is an open source MVVM framework for web applications. Prior to 4.2.11, 4.3.15, and 5.0.0-preview09-final, a route containing multiple unconstrained parameters in one path segment can cause excessive regular-expression backtracking in DotvvmRoute.IsMatch when a remote requester supplies a long near-match path. DotvvmRouteParser.RouteRegex previously had no matching timeout. Patched runtimes retry with the .NET non-backtracking engine, while runtimes that do not support non-backtracking matching return HTTP 503 after the one-second timeout in DotvvmRoutingMiddleware. This issue is fixed in versions 4.2.11, 4.3.15, and 5.0.0-preview09-final.

References

• https://github.com/riganti/dotvvm/commit/1635245b5eaf9ccf8e3536b9d8b1941819526585
• https://github.com/riganti/dotvvm/commit/4fc26a8591c76fb92ed701352c2a84120cf926c5
• https://github.com/riganti/dotvvm/commit/5728ab80fff9af883b44d11c118d2e8a8991dcd4
• https://github.com/riganti/dotvvm/releases/tag/v4.3.15
• https://github.com/riganti/dotvvm/releases/tag/v5.0.0-preview09