Is CVE-2026-57577 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-57577 being exploited in the wild.

How severe is CVE-2026-57577?

Informational severity, with a CVSS score of 5.3, published 14 September 2026.

Which products and versions are affected?

DotVVM DotVVM before 4.2.11, 4.3.x before 4.3.15, 5.0.0-preview before preview09-final.

Is there a fix for CVE-2026-57577?

A patch was published on 2026-06-18: Patches committed to main branch (versions 4.2.11, 4.3.15, 5.0.0-preview09-final) Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-57577 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-57577?

Check whether anything you run is named in the advisory. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-57577: DotVVM regex denial of service in route matching

CVE-2026-57577 · Severity: info · CVSS 5.3 · Published 2026-09-14

DotVVM is an open source MVVM web framework used to build .NET web applications. A flaw in its routing engine allows an attacker to send specially crafted requests with long paths that cause excessive CPU consumption through regex backtracking, leading to service unavailability. Affected applications return HTTP 503 errors and become unresponsive to legitimate traffic during an attack.

Quick answers

Is CVE-2026-57577 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-57577 being exploited in the wild.
How severe is CVE-2026-57577?: Informational severity, with a CVSS score of 5.3, published 14 September 2026.
Which products and versions are affected?: DotVVM DotVVM before 4.2.11, 4.3.x before 4.3.15, 5.0.0-preview before preview09-final.
Is there a fix for CVE-2026-57577?: A patch was published on 2026-06-18: Patches committed to main branch (versions 4.2.11, 4.3.15, 5.0.0-preview09-final) Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-57577 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-57577?: Check whether anything you run is named in the advisory. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

The vulnerability is a regular expression denial of service (ReDoS) in DotvvmRoute.IsMatch when processing routes containing multiple unconstrained parameters in a single path segment. DotvvmRouteParser.RouteRegex previously lacked a matching timeout. A remote attacker can send HTTP requests with long near-match paths to trigger catastrophic backtracking in the regex engine. The attack is network-accessible and requires no authentication. On patched runtimes, the code retries with the .NET non-backtracking engine; older runtimes timeout after one second in DotvvmRoutingMiddleware and return HTTP 503. The fix is available in versions 4.2.11, 4.3.15, and 5.0.0-preview09-final.

Affected products

DotVVM DotVVM before 4.2.11, 4.3.x before 4.3.15, 5.0.0-preview before preview09-final

Timeline

2026-09-14: disclosed
2026-06-18: patched: Patches committed to main branch (versions 4.2.11, 4.3.15, 5.0.0-preview09-final)

References

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