CVE-2026-96764 in mooncake
Summary
by MITRE • 09/24/2026
A weakness has been identified in kvcache-ai mooncake up to 0.3.12/0.3.14-rc1. Impacted is the function MasterService::GetReplicaListByRegex of the component Regular Expression Handler. Executing a manipulation can lead to allocation of resources. The attack may be performed from remote. The exploit has been made available to the public and could be used for attacks. The vendor was contacted early about this disclosure but did not respond in any way.
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Analysis
by VulDB Data Team • 09/24/2026
The vulnerability identified within kvcache-ai mooncake versions up to 0.3.12 and 0.3.14-rc1 represents a significant security risk stemming from improper handling of regular expressions by the MasterService component. Specifically, the function GetReplicaListByRegex is susceptible to an algorithmic complexity flaw that allows for excessive resource allocation when processing crafted input. This issue falls under the category of ReDoS or Regular Expression Denial of Service, which is formally classified as CWE-1335 in the Common Weakness Enumeration database. The core technical flaw lies in the regex engine's inability to efficiently process certain patterns containing nested quantifiers or ambiguous backtracking paths. When an attacker supplies a specifically crafted regular expression string designed to trigger exponential time complexity during matching operations, the underlying system is forced into a state of continuous computation without yielding control. This behavior effectively consumes CPU cycles and memory resources at a rate that can quickly overwhelm the host environment, leading to service degradation or complete unavailability for legitimate users.
The operational impact of this vulnerability is severe due to its remote exploitability. Since the GetReplicaListByRegex function is part of the MasterService component, it likely handles requests from various clients within the distributed system architecture. An attacker positioned remotely can send maliciously constructed HTTP requests or API calls containing the problematic regex patterns. Upon receipt, the service attempts to evaluate these expressions against internal data structures or configuration parameters. The resulting computational explosion does not necessarily require authentication in many default configurations, allowing unauthenticated actors to initiate denial-of-service attacks. This capability transforms a standard web service into an easy target for resource exhaustion campaigns. Furthermore, because this vulnerability has been publicly disclosed and exploit code is available, the window of opportunity for malicious exploitation is wide open. Organizations relying on these specific versions are at immediate risk unless they implement compensating controls or upgrade to patched releases where such regex patterns have been sanitized or optimized with atomic grouping features that prevent catastrophic backtracking.
Mitigation strategies must address both the technical flaw and the broader operational exposure. The primary remediation step is to update the kvcache-ai mooncake software to a version later than 0.3.14-rc1, assuming the vendor has released patches that resolve this specific regex handling issue. In cases where immediate patching is not feasible due to dependency constraints or testing requirements, network-level defenses should be employed. Implementing rate limiting on endpoints exposed by the MasterService can help mitigate the impact of rapid-fire requests designed to trigger the vulnerability. Additionally, deploying Web Application Firewalls with rules capable of detecting anomalous regex patterns may provide a layer of protection against automated exploitation attempts. It is also advisable to review access controls around the GetReplicaListByRegex endpoint to ensure that only authorized services can invoke it, thereby reducing the attack surface available to remote attackers. Given the vendor's lack of response to early disclosure efforts, organizations should consider this vulnerability as critical and act independently to secure their infrastructure against known exploit kits circulating in public repositories. This situation highlights the importance of maintaining up-to-date software inventories and having incident response plans that account for vulnerabilities where patch availability is delayed or uncertain.