CVE-2026-92870 in Pgpool-II
Summary
by MITRE • 09/30/2026
A stack-based buffer overflow vulnerability exists in Pgpool-II, which may allow an unauthenticated attacker to cause abnormal process termination.
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Analysis
by VulDB Data Team • 09/30/2026
The identified vulnerability represents a critical security flaw within the Pgpool-II software suite, specifically manifesting as a stack-based buffer overflow. This type of memory corruption error occurs when data is written beyond the allocated boundary of a fixed-size buffer located on the call stack. In the context of network-facing services like Pgpool-II, which acts as a connection pooler and load balancer for PostgreSQL databases, such vulnerabilities are particularly severe because they can be triggered remotely by an unauthenticated attacker. The root cause typically involves insufficient validation or bounds checking when processing incoming requests, allowing maliciously crafted input to overwrite adjacent memory locations on the stack. This overwriting disrupts the normal flow of execution, often corrupting critical control data such as return addresses or function pointers.
From a technical perspective, the exploitation of this vulnerability does not necessarily require code execution in its initial phase but primarily aims at causing denial of service through abnormal process termination. When the buffer overflow occurs, it triggers an exception that leads to the immediate crash of the Pgpool-II worker process. Since Pgpool-II relies on multiple backend processes to handle database connections efficiently, the termination of one or more workers can degrade performance significantly or cause a complete outage if critical nodes are affected. While modern operating systems employ mitigations such as stack canaries and non-executable stacks that may prevent arbitrary code execution in some scenarios, these protections do not fully mitigate the risk of service disruption caused by process crashes. The attacker does not need valid credentials to exploit this flaw, making it a high-risk vector for distributed denial-of-service attacks against database infrastructure.
The operational impact of this vulnerability extends beyond simple availability loss. Pgpool-II is often deployed as a single point of failure or a critical gateway in enterprise database architectures. Its unavailability prevents applications from establishing new connections to the backend PostgreSQL servers, effectively halting data-driven operations. Furthermore, frequent process restarts can lead to resource exhaustion and instability within the broader system environment. The lack of authentication requirement means that any entity with network access to the Pgpool-II service port can attempt exploitation, increasing the attack surface significantly in public-facing or poorly segmented internal networks. This aligns with common vulnerability classifications such as CWE-121, which describes stack-based buffer overflow, and relates to ATT&CK techniques involving resource hijacking for denial of service effects rather than direct privilege escalation at this stage.
To mitigate the risks associated with this vulnerability, immediate patching is required by upgrading Pgpool-II to a version that includes fixes for the specific memory handling flaws identified in the stack-based buffer overflow. Administrators should verify their current software versions against vendor advisories and apply updates promptly. In addition to patching, network-level controls such as firewalls or intrusion prevention systems can be configured to restrict access to the Pgpool-II service ports only from trusted application servers, thereby reducing exposure to unauthenticated attackers. Implementing rate limiting on incoming connections can also help mitigate potential denial-of-service attempts by detecting and blocking anomalous traffic patterns before they trigger the underlying memory corruption flaw. Regular security audits and static code analysis during development cycles are recommended to prevent similar buffer handling issues in future software releases.