# CVE-2026-57577: DotVVM: ReDOS in routing

> Remote attackers can cause excessive CPU consumption and service unavailability by sending crafted URLs to DotVVM applications with unconstrained route parameters.

- **Severity:** High 8.2 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 14 Sep 2026
- **Updated:** 14 Sep 2026
- **Also known as:** GHSA-c2g3-c4gc-w5wg

## What is CVE-2026-57577?

CVE-2026-57577 is a high-severity denial of service vulnerability in riganti dotvvm, published on 14 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official 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.

Weakness: CWE-1333 (Inefficient Regular Expression Complexity)

## Which versions are affected by CVE-2026-57577?


## How do I fix CVE-2026-57577?

No fix has been published for CVE-2026-57577 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-57577 being exploited?

There is no known exploitation of CVE-2026-57577 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-57577 and fix it if it is affected.

What it is: CVE-2026-57577 is a high-severity denial of service vulnerability in riganti dotvvm, published on 14 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-57577 in the wild and no public exploit code.

Affected product: riganti dotvvm. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-57577/ (Markdown: https://insights.sbomify.com/CVE-2026-57577/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-57577
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-57577
- OSV: https://osv.dev/vulnerability/CVE-2026-57577

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-57577/
Summaries are generated and may contain mistakes; the official description above is the record.