CVE-2026-83663 in Thrift
Summary
by MITRE • 10/02/2026
Uncontrolled Recursion vulnerability in Apache Thrift go bindings.
Both Go transports satisfy a read out of a buffered frame and, when that frame yields no payload bytes, read the next frame and call `Read` again instead of looping. A peer produces such a frame for 4 bytes in `TFramedTransport` (a declared size of zero) or 18 bytes in `THeaderTransport` (a header block that fills the frame), so nothing bounds the depth. The Go stack limit is reached as a `fatal error`, which `recover()` cannot catch, so the whole process dies.
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 vulnerability identified in Apache Thrift Go bindings constitutes a critical uncontrolled recursion flaw that leads to service denial through stack exhaustion. This security defect resides within the transport layer implementation of the Go client and server libraries, specifically affecting how framed data is processed during deserialization operations. The core issue stems from an incorrect loop structure used when reading buffered frames. In normal operation, these transports are designed to read a frame header to determine payload size, followed by reading that specific amount of payload bytes. However, in the flawed implementation, if a frame yields no actual payload bytes despite being declared as having content or requiring further processing, the code does not enter an iterative loop to continue consuming subsequent frames. Instead, it recursively calls its own Read function. This design choice fundamentally breaks the expected state machine for transport protocols and creates a direct path to stack overflow under specific input conditions.
The technical mechanics of this flaw rely on how different Thrift transports handle frame boundaries. In TFramedTransport, an attacker can craft a message with a declared size of zero bytes but structured in a way that triggers the recursive read logic without terminating cleanly. Similarly, THeaderTransport allows for the creation of header blocks that fill the frame completely, effectively masking the lack of payload data while still triggering the recursive call path. Because there is no counter or depth limit imposed on these recursive invocations, each failed attempt to process a zero-payload or fully-headered frame results in another stack frame being allocated. As this recursion continues unchecked, it rapidly consumes available memory and eventually hits the Go runtime's hard stack limit. This condition manifests as a fatal error that cannot be intercepted by standard panic recovery mechanisms, resulting in an immediate and ungraceful termination of the entire application process rather than a recoverable exception or connection reset.
From an operational perspective, this vulnerability represents a severe denial-of-service risk for any service relying on Apache Thrift Go bindings to handle network traffic. An attacker does not need complex exploitation techniques; they merely need to send malformed frames that trigger the unbounded recursion pattern. Once triggered, the application crashes instantly, taking down all concurrent connections and requiring manual intervention or process restarts to restore availability. This impacts high-throughput microservices architectures where Thrift is commonly used for inter-service communication. The lack of graceful degradation means that a single malicious packet can disrupt service continuity, leading to significant downtime and potential data loss if transactions are in progress at the time of the crash.
This vulnerability aligns with CWE-675, which describes operations on uncontrolled recursion depth, as well as CWE-400 regarding unconstrained resource consumption. In terms of offensive security frameworks, this behavior is consistent with ATT&CK technique T1499, Endpoint Denial of Service, specifically under the sub-category of Resource Exhaustion via Overflow or Loop. The flaw exploits a fundamental misunderstanding of iterative versus recursive control flow in handling variable-length input streams, highlighting the importance of rigorous validation and loop-based processing for network protocol implementations rather than relying on recursion for stream consumption.
To mitigate this risk, organizations must upgrade Apache Thrift to version 0.25.0 or later, where the transport layer logic has been corrected to use iterative loops instead of recursive calls when handling frame reads. This ensures that even if a peer sends malformed frames with zero payload or excessive headers, the system will process them iteratively without exhausting the call stack. Until an upgrade is feasible, administrators should consider placing reverse proxies in front of Thrift services to inspect and filter out anomalous traffic patterns, although this provides only partial mitigation as the attack vector operates at a low level within the protocol parsing logic. Regular security audits focusing on network transport implementations are recommended to prevent similar recursion-based denial-of-service vulnerabilities in other components of the software stack.