CVE-2026-25087 is a Use After Free (CWE-416) vulnerability affecting the Apache Arrow C++ library versions 15.0.0 through 23.0.0. The flaw arises when reading Arrow IPC files (not IPC streams) with pre-buffering enabled via the RecordBatchFileReader::PreBufferMetadata API. Specifically, if the IPC file contains data with variadic buffers—such as Binary View or String View types—the interaction of multiple variadic buffers in a record batch column combined with multi-threaded IO timing can cause a write operation to a dangling pointer. This dangling pointer write involves a std::shared_ptr<Buffer> object, which is not directly attacker-controlled, reducing the likelihood of arbitrary code execution. The vulnerability is limited to the C++ implementation since pre-buffering is not exposed in other language bindings like Python, Ruby, or C GLib, which remain unaffected. The primary consequence is potential random crashes or memory corruption when processing specially crafted IPC files. If an application ingests IPC files from untrusted sources and has pre-buffering enabled, denial of service attacks are plausible. More targeted attacks such as confidential data extraction are theoretically possible but highly improbable due to the complexity of controlling memory allocation and IO timing in multi-threaded environments. The vulnerability was publicly disclosed on February 17, 2026, with no known exploits in the wild. Mitigation involves either disabling pre-buffering or upgrading to Apache Arrow 23.0.1, which contains the fix. The CVSS v3.1 base score is 7.0, indicating a high severity with network attack vector, high attack complexity, no privileges required, no user interaction, and partial impact on confidentiality, integrity, and availability.

The primary impact of CVE-2026-25087 is denial of service through application crashes or memory corruption when processing maliciously crafted Arrow IPC files with pre-buffering enabled. Organizations using Apache Arrow C++ in data processing pipelines that consume IPC files from untrusted or semi-trusted sources could experience service disruptions, potentially affecting data analytics, real-time processing, or ETL workflows. Although the vulnerability does not readily allow remote code execution or data leakage, the instability caused by memory corruption could lead to broader system reliability issues or cascading failures in dependent services. Since the vulnerability requires enabling a specific pre-buffering feature not enabled by default and is limited to the C++ implementation, the attack surface is somewhat constrained. However, high-value targets relying on Apache Arrow C++ for large-scale data processing, such as cloud service providers, financial institutions, and research organizations, may face operational risks. The lack of known exploits reduces immediate threat but does not eliminate future risk, especially if attackers develop techniques to exploit the memory corruption more effectively. The vulnerability's network attack vector means remote attackers can trigger it by supplying crafted IPC files, increasing exposure in distributed environments.

1. Audit all applications and services using Apache Arrow C++ to determine if pre-buffering is enabled via RecordBatchFileReader::PreBufferMetadata. 2. If pre-buffering is enabled, consider disabling it to eliminate the vulnerability, understanding that this may impact performance. 3. Upgrade Apache Arrow C++ to version 23.0.1 or later, where the vulnerability is patched, to maintain pre-buffering benefits without risk. 4. Implement strict input validation and source verification for IPC files ingested from external or untrusted sources to reduce the risk of malicious file processing. 5. Employ runtime memory protection mechanisms such as AddressSanitizer or similar tools during development and testing to detect use-after-free conditions early. 6. Monitor application logs and crash reports for signs of memory corruption or unexpected terminations related to IPC file processing. 7. Isolate data processing environments handling IPC files from untrusted sources to limit potential denial of service impact. 8. Stay informed on Apache Arrow security advisories and apply patches promptly.