CVE-2026-41602: Apache Thrift Integer Overflow Vulnerability

CVE-2026-41602 Overview

An Integer Overflow or Wraparound vulnerability has been identified in Apache Thrift's TFramedTransport Go language implementation. This vulnerability affects Apache Thrift versions prior to 0.23.0 and can be exploited remotely over the network without requiring any privileges or user interaction. The flaw in integer handling within the TFramedTransport component can lead to denial of service conditions when processing maliciously crafted requests.

Critical Impact

This integer overflow vulnerability in a widely-used RPC framework can result in service availability disruption, potentially affecting distributed systems and microservice architectures that rely on Apache Thrift for inter-service communication.

Affected Products

• Apache Thrift versions before 0.23.0
• Applications using TFramedTransport in Go language implementations
• Distributed systems leveraging Apache Thrift for RPC communication

Discovery Timeline

• April 28, 2026 - CVE-2026-41602 published to NVD
• April 28, 2026 - Last updated in NVD database

Technical Details for CVE-2026-41602

Vulnerability Analysis

This vulnerability stems from improper handling of integer arithmetic within the TFramedTransport implementation for the Go programming language. The TFramedTransport protocol is used to frame messages with a fixed-length header that specifies the size of the payload that follows. When this size value is manipulated to cause an integer overflow, the resulting value wraps around, leading to unexpected behavior in memory allocation or buffer handling operations.

The vulnerability is classified under CWE-190 (Integer Overflow or Wraparound), which describes scenarios where arithmetic operations produce values exceeding the maximum representable range for the data type, causing the value to wrap to an unexpectedly small or negative number.

Root Cause

The root cause lies in insufficient validation of frame size values received from network input before performing arithmetic operations. In Go, integer overflow does not trigger runtime exceptions by default, meaning unchecked arithmetic can silently produce incorrect values. When a large frame size value causes an integer overflow during buffer allocation calculations, the resulting undersized buffer allocation can lead to crashes or resource exhaustion when the actual payload is processed.

Attack Vector

An attacker can exploit this vulnerability by sending specially crafted Thrift protocol messages with malicious frame size headers to services using the vulnerable TFramedTransport implementation. The attack can be executed remotely over the network without authentication, making it accessible to any attacker who can reach the affected service endpoint.

The exploitation process involves:

1. Establishing a connection to a service using Apache Thrift with TFramedTransport
2. Sending a message with a frame size value designed to trigger integer overflow
3. The overflow causes improper memory handling, resulting in denial of service

Since no verified code examples are available, security researchers are advised to review the Apache Mailing List Thread and the Openwall OSS-Security Discussion for additional technical details regarding the vulnerability mechanism.

Detection Methods for CVE-2026-41602

Indicators of Compromise

• Unexpected service crashes or restarts in Thrift-based applications
• Abnormal memory consumption patterns in Go services using TFramedTransport
• Network traffic containing Thrift messages with unusually large or negative frame size values
• Application logs showing panic states or out-of-memory errors in Thrift transport layers

Detection Strategies

• Deploy network intrusion detection rules to identify Thrift protocol messages with anomalous frame size headers
• Implement application-level logging to capture frame size values before processing
• Monitor Go application runtime metrics for signs of memory allocation failures or panics
• Use SentinelOne Singularity to detect anomalous process behavior indicative of denial of service attacks

Monitoring Recommendations

• Configure alerting for sudden increases in service restarts or crash rates
• Monitor network traffic patterns for connections sending malformed Thrift frames
• Implement distributed tracing to identify the source of problematic requests
• Enable runtime profiling to detect memory allocation anomalies in production environments

How to Mitigate CVE-2026-41602

Immediate Actions Required

• Upgrade Apache Thrift to version 0.23.0 or later immediately
• Audit all services using the Go TFramedTransport implementation
• Implement network-level rate limiting and access controls for Thrift services
• Consider temporarily switching to alternative transport implementations if immediate upgrade is not possible

Patch Information

Apache has released version 0.23.0 which fixes this integer overflow vulnerability. Users are strongly recommended to upgrade to this version or later. The fix implements proper bounds checking on frame size values before performing arithmetic operations that could result in overflow conditions.

For detailed patch information and upgrade guidance, refer to the Apache Mailing List Thread.

Workarounds

• Deploy reverse proxies or API gateways with protocol-aware filtering to validate Thrift frame sizes before they reach backend services
• Implement application-level validation of frame size values with explicit overflow checks before processing
• Use network segmentation to limit exposure of Thrift services to trusted networks only
• Consider wrapping TFramedTransport with custom size validation logic as a temporary measure

# Verify Apache Thrift version in your Go project
go list -m github.com/apache/thrift | grep -E "v[0-9]+\.[0-9]+\.[0-9]+"

# Update to patched version
go get github.com/apache/thrift@v0.23.0
go mod tidy