CVE-2026-92834 in Thrift
Summary
by MITRE • 10/02/2026
Use of uninitialized resource, Return of wrong status code vulnerability in Apache Thrift C++ WebSocket server.
This issue affects Apache Thrift: before 0.25.0.
Users are recommended to upgrade to version 0.25.0, which fixes the issue.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 10/02/2026
The identified security flaw resides within the Apache Thrift C++ implementation of its WebSocket server component, specifically affecting versions prior to release 0.25.0. This vulnerability is categorized as a use of uninitialized resource combined with the return of an incorrect status code during connection handling or request processing phases. In complex networked applications like distributed RPC frameworks, proper state management and error reporting are critical for maintaining system integrity and preventing exploitation by malicious actors seeking to disrupt service availability or extract sensitive information through malformed inputs.
From a technical perspective, the core issue stems from improper initialization of internal data structures or pointers used during WebSocket handshake negotiations or message frame processing. When specific edge cases occur, such as receiving unexpected header values or encountering abrupt connection terminations, the server may proceed with operations using memory that has not been properly zeroed out or assigned valid default values. This leads to undefined behavior where the application logic relies on garbage data from previous stack allocations or heap segments. Concurrently, instead of returning a standardized error code indicating failure due to invalid input or internal state corruption, the server returns an incorrect status code. This misreporting can mask the true nature of the failure, making debugging difficult for administrators and potentially allowing attackers to infer internal implementation details through differential analysis of response codes.
The operational impact of this vulnerability is primarily centered around service instability and potential information disclosure. The use of uninitialized memory can lead to crashes or segmentation faults when the server attempts to dereference invalid pointers, resulting in a denial of service condition for clients attempting to connect via WebSocket protocols. Furthermore, if the uninitialized data contains remnants of previously processed sensitive requests, such as authentication tokens or internal identifiers, there is a risk that this information could be inadvertently transmitted back to the client through malformed responses. The incorrect status code exacerbates these issues by preventing proper error handling on the client side, potentially leading to cascading failures in dependent services that rely on accurate HTTP-like response semantics for flow control and retry logic.
This vulnerability aligns with Common Weakness Enumeration (CWE) identifiers such as CWE-457, which describes the use of an uninitialized variable, and CWE-252, concerning unchecked return values or improper handling of error conditions in API calls. In terms of attack vectors, this flaw can be leveraged within the MITRE ATT&CK framework under techniques related to Denial of Service (T1499) due to resource exhaustion via crashes, and potentially Information Discovery (T1057) if memory contents are leaked through response anomalies. Attackers could craft specific WebSocket frames that trigger these uninitialized states repeatedly, causing sustained disruption to the Thrift service endpoint.
To mitigate this risk, organizations running Apache Thrift C++ servers with WebSocket support must upgrade immediately to version 0.25.0 or later, where these initialization checks and status code returns have been corrected by the development team. For environments that cannot yet patch due to compatibility constraints, implementing a reverse proxy in front of the Thrift server can provide an additional layer of defense. Configuring the proxy to drop malformed WebSocket frames or enforce strict connection timeouts can prevent attackers from triggering the vulnerable code paths within the application itself. Additionally, enabling comprehensive logging and monitoring for unusual HTTP status codes returned by the service can help detect potential exploitation attempts in real time, allowing security teams to respond before significant damage occurs. Regular vulnerability scanning of external-facing services is also recommended to ensure that no unpatched instances remain exposed to the internet or internal networks where lateral movement could occur.