CVE-2026-94638 in Thrift
Summary
by MITRE • 10/02/2026
Allocation of resources without limits or throttling vulnerability in Apache Thrift PHP bindings.
This issue affects Apache Thrift: before 0.25.0.
Users are recommended to upgrade to version 0.25.0, which fixes the issue.
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Analysis
by VulDB Data Team • 10/02/2026
The identified vulnerability within the Apache Thrift PHP bindings represents a critical failure in resource management mechanisms, specifically categorized under CWE-770: Allocation of Resources Without Limits or Throttling. This flaw allows an attacker to trigger excessive consumption of system resources such as memory, CPU cycles, or network bandwidth without any internal safeguards to cap usage. In the context of distributed systems and microservices where Apache Thrift is frequently employed for high-performance RPC communication, this weakness can be exploited to degrade service availability significantly. The absence of throttling means that a single malicious request or a series of rapid requests from an unauthenticated or authenticated user can cause the server process handling PHP bindings to consume disproportionate amounts of memory and processing power. This lack of control over resource allocation is particularly dangerous in shared hosting environments or containerized deployments where one compromised service can impact the stability of neighboring services due to resource starvation.
From a technical perspective, the vulnerability stems from how the Thrift framework processes incoming data structures in PHP versions prior to 0.25.0. When parsing complex nested objects or large payloads, the library may allocate memory dynamically without verifying if the size exceeds reasonable thresholds or system limits. An attacker can craft specially formatted messages that force the interpreter into deep recursion or massive array allocations, leading to a denial of service condition known as an application-layer DDoS attack. This aligns with MITRE ATT&CK technique T1496: Resource Hijacking, where adversaries leverage computational resources for their own benefit or to disrupt operations by exhausting system capacity. The impact extends beyond simple downtime; it can lead to cascading failures in upstream load balancers and downstream dependent services that rely on the availability of this Thrift-based endpoint.
The operational impact of this vulnerability is severe, primarily affecting the confidentiality, integrity, and most notably, the availability of applications relying on Apache Thrift for inter-service communication. While direct code execution or data exfiltration may not be immediate outcomes of resource exhaustion alone, the resulting instability can mask other malicious activities or force administrators to take systems offline for recovery, thereby disrupting business continuity. In high-throughput environments, even minor inefficiencies in memory management are amplified by volume, making this vulnerability a prime target for automated scanning tools and opportunistic attackers seeking quick wins against unpatched infrastructure. The lack of input validation regarding payload size or structure complexity is the root cause, allowing external actors to dictate the resource footprint of the server process arbitrarily.
To mitigate this risk, organizations must prioritize upgrading Apache Thrift PHP bindings to version 0.25.0 or later immediately upon availability in their deployment pipelines. This release incorporates fixes that enforce stricter limits on memory allocation and introduce throttling mechanisms to prevent runaway resource consumption during data parsing. In addition to the software upgrade, defensive measures should include implementing network-level rate limiting using reverse proxies such as Nginx or Apache HTTP Server to cap the number of requests per second from any single IP address. Furthermore, application-layer monitoring tools should be configured to alert on abnormal spikes in memory usage or request latency associated with Thrift endpoints. Regular security assessments and penetration testing focused on input validation and resource management will help identify similar weaknesses before they can be exploited in production environments.