CVE-2026-88763 in Service Interconnect
Summary
by MITRE • 09/10/2026
A flaw was found in the skupper-router component of Red Hat Service Interconnect, which is used to provide secure communication between distributed services. The issue occurs when the router processes a specially crafted network message using its AMQP field parser. Due to a lack of bounds on recursion during parsing, the router can run out of stack memory and crash, leading to a denial of service for the interconnected network.
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Analysis
by VulDB Data Team • 09/10/2026
The vulnerability identified in the skupper-router component of Red Hat Service Interconnect represents a critical reliability risk within distributed microservice architectures that rely on this technology for secure communication. Skupper-router functions as an AMQP 1.0 router, facilitating message routing and service discovery across disparate network segments or cloud environments. The core technical flaw resides within the Advanced Message Queuing Protocol field parser, which is responsible for interpreting incoming network messages to extract relevant data fields such addresses, properties, and payloads. During normal operation, this parser must handle a wide variety of message structures sent by connected clients and peer routers. However, the implementation fails to enforce strict bounds on recursive parsing operations when processing specific AMQP types that allow for nested or self-referential structures.
When an attacker sends a specially crafted network message containing deeply nested or recursively defined AMQP fields, the parser enters an uncontrolled recursion loop. Because there is no mechanism to limit the depth of this recursion, each level of nesting consumes additional stack memory allocated by the operating system for the router process. As the parsing continues without termination conditions based on depth limits, the available stack space is rapidly exhausted. This condition leads directly to a stack overflow error, causing the skupper-router process to crash abruptly. The immediate operational impact is a denial of service affecting not only the specific node running the compromised router but potentially the entire interconnected network if that node serves as a critical routing hub or bridge between segments.
The consequences of this vulnerability extend beyond simple downtime for individual services. In a distributed system relying on Red Hat Service Interconnect, the loss of connectivity can disrupt data synchronization, break service-to-service communication chains, and prevent configuration updates from propagating correctly. This denial of service effectively isolates parts of the infrastructure, leading to potential data inconsistency or complete operational paralysis depending on the topology's reliance on that specific router instance. The attack vector is particularly concerning because it requires only network access to send a malformed message, potentially allowing remote attackers who can reach the AMQP port to trigger the crash without needing authentication if the service exposes unauthenticated endpoints for certain operations.
From a classification perspective, this vulnerability aligns with CWE-675, which describes unintentional or unintended recursion, and more broadly with CWE-400 regarding resource exhaustion issues such as stack overflow. In terms of offensive security frameworks like MITRE ATT&CK, this flaw facilitates Denial of Service attacks against networked systems, specifically targeting the availability component of the CIA triad by exploiting application-level logic flaws rather than infrastructure vulnerabilities. The lack of input validation and depth limiting in the AMQP parser is a common pattern in protocol implementations that prioritize performance over strict structural constraints during parsing phases.
To mitigate this risk, administrators should ensure that Red Hat Service Interconnect packages are updated to versions where the skupper-router has been patched with proper recursion limits implemented in its AMQP field parser. This patch introduces checks that terminate parsing operations if a predefined depth threshold is exceeded, thereby preventing stack exhaustion even when processing maliciously crafted messages. Additionally, network-level mitigations can be employed by restricting access to the AMQP ports used by skupper-router using firewall rules or service mesh policies, ensuring that only trusted and authorized clients can send messages to these endpoints. Implementing rate limiting on incoming connections may also help reduce the impact of automated fuzzing attacks attempting to exploit this flaw before a patch is applied. Regular security audits focusing on protocol parsers in critical infrastructure components are recommended to identify similar recursion or resource exhaustion vulnerabilities early in the development lifecycle.