CVE-2026-67552 in Qpid Proton Dotnet
Summary
by MITRE • 08/05/2026
A pre-authentication attacker could leverage type nesting to cause a StackOverflowError potentially leading to denial of service.
This issue affects Apache Qpid Proton-Dotnet through 1.0.0.
Users are recommended to upgrade to version 1.1.0, which fixes the issue
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Analysis
by VulDB Data Team • 08/05/2026
The vulnerability described represents a pre-authentication stack overflow condition that can be exploited by remote attackers without requiring authentication credentials. This type of vulnerability falls under the category of denial of service attacks where an attacker can manipulate input data to cause abnormal program behavior. The specific flaw manifests through type nesting mechanisms within the Apache Qpid Proton-Dotnet library, which is a .NET implementation of the AMQP protocol for messaging systems. When an attacker crafts malicious input that exploits nested type structures, the application's stack memory consumption grows uncontrollably until it exhausts available resources.
The technical implementation of this vulnerability stems from insufficient input validation and improper handling of nested data structures within the library's deserialization process. The attack leverages the inherent complexity of type nesting to create recursive memory allocation patterns that eventually lead to a StackOverflowError. This error occurs when the call stack exceeds its allocated memory space, typically due to infinite recursion or deeply nested function calls. In the context of Apache Qpid Proton-Dotnet, this issue affects version 1.0.0 and earlier releases, indicating that the fix was implemented in version 1.1.0 as a remediation measure.
From an operational impact perspective, this vulnerability poses significant risk to systems relying on Apache Qpid Proton-Dotnet for message broker communications. A successful exploitation can result in complete service disruption, requiring system administrators to restart affected services manually. The pre-authentication nature of the attack means that any network-connected system using vulnerable versions is immediately at risk, as attackers do not need valid credentials to initiate the exploit. Organizations running messaging infrastructure components that depend on this library may experience extended downtime and potential business interruption if the vulnerability is exploited in production environments.
The mitigation strategy involves upgrading to Apache Qpid Proton-Dotnet version 1.1.0 or later, which incorporates defensive measures against type nesting attacks. This upgrade addresses the core issue by implementing proper input validation and limiting recursive depth during deserialization operations. Security practitioners should also consider network segmentation controls and monitoring for unusual traffic patterns that might indicate exploitation attempts. The vulnerability aligns with CWE-770, which addresses allocation of resources without adequate limits or refreshes, and can be mapped to ATT&CK technique T1499.3 for denial of service through resource exhaustion. Organizations should perform comprehensive testing of the upgrade process to ensure compatibility with existing messaging workflows while maintaining operational continuity during the remediation phase.