EUVD-2026-77699Vulnerability Assessment
| Weakness |
CWE
ASVS 5.0
V2 - Validation and Business Logic Regex complexity limits
MITRE ATT&CK
1 technique across 1 tactic: Impact The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
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Alert meAnalysisAIv1 – Sep 15, 2026
A regular-expression denial-of-service (ReDoS) flaw in DotVVM's routing engine (DotvvmRoute.IsMatch / DotvvmRouteParser.RouteRegex) lets a remote requester send a long, near-matching URL path and force excessive regex backtracking, tying up a worker thread for roughly one second per request. Only applications that declare routes with multiple unconstrained parameters inside a single path segment (e.g. "edit/{a}-{b}-{c}/done") are exposed; fully constrained or slash-separated routes are unaffected. The issue is fixed in DotVVM 4.2.11, 4.3.15 and 5.0.0-preview09-final, which apply a one-second regex timeout and then permanently switch the route to the .NET non-backtracking engine (or return HTTP 503 on runtimes older than .NET 8). There is no CISA KEV entry and no public exploit code identified at time of analysis, and CISA's SSVC assessment rates Exploitation as none and Automatable as no.
Affected VersionsENISA
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 2 packages in euvd
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Severity by source
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
Primary rating from Vendor (GitHub_M) · only source for this CVE.
CVSS VectorVendor: GitHub_M
Lifecycle Timeline
2DescriptionCVE.org
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.
Technical POC Analysis
CWE-1333 (Inefficient Regular Expression Complexity).
Full technical POC analysis - root cause, step-by-step exploitation and patch breakdown - is part of the Pro and Business plans.
Threat Intelligence Overview
NVD
CVE.org
EPSS
Vulnrichment
GitHub
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Denial of Service attacks render applications or systems unavailable by overwhelming resources or triggering failure conditions.
Missing authorization in DotVVM's AuthorizeActionFilter causes any ASP.NET web application that relies on that filter to
Unrestricted file upload in DotVVM before 4.2.11, 4.3.15, and 5.0.0-preview09-final lets unauthenticated remote users pu
Exploit-DB