CVE-2026-25087: Critical Memory Corruption Flaw in Apache Arrow C++ IPC Reader Could Trigger Application Crashes Under Specific Configurations

Apache Arrow C++ – Use-After-Free (Memory Corruption / Denial of Service)

CVE ID: CVE-2026-25087
Affected Component: Apache Arrow C++ (IPC File Reader)
Affected Versions: 15.0.0 through 23.0.0
Fixed Version: 23.0.1 and later
CVSS v3.1: 7.0 (High)
Vector: AV:N / AC:H / PR:N / UI:N / S:U / C:L / I:L / A:H
Severity: High
Exploitability: Possible under specific conditions
Exploit Availability: No public weaponized exploit observed at this time
Primary Impact: Application crash, memory corruption, service instability

Official Patch / Upgrade Link:
https://github.com/apache/arrow/pull/48925

Overview

CVE-2026-25087 is a use-after-free vulnerability in the Apache Arrow C++ implementation, specifically within the IPC file reader when metadata pre-buffering is enabled. The issue occurs due to improper memory lifetime management during concurrent metadata handling. Under certain execution paths, memory is freed while still being referenced, and a write operation later occurs on that freed memory.

This condition may result in memory corruption, application crashes, or denial of service. While theoretical remote code execution cannot be fully ruled out in memory corruption scenarios, the structure of this bug makes reliable exploitation for arbitrary code execution highly complex and unlikely.

The vulnerability does not affect the IPC stream reader and does not impact language bindings such as Python (pyarrow), Ruby, or GLib, because the vulnerable API is not exposed there.

Technical Details

The flaw exists in the RecordBatchFileReader::PreBufferMetadata functionality of Apache Arrow C++. This optional performance feature attempts to pre-load metadata for improved read efficiency.

When the following conditions are met:

IPC file reader is used (not stream reader)
Pre-buffering is explicitly enabled
The IPC file contains variadic or non-inline buffers (e.g., Binary View or String View types)
Multi-threaded IO execution occurs

A race condition may occur between buffer allocation and deallocation. A std::shared_ptr<Buffer> object may be written into a memory region that has already been freed. This results in a classic use-after-free condition (CWE-416).

The value written into freed memory is internally derived and not attacker-controlled, which significantly reduces the likelihood of controlled code execution. However, heap corruption and process termination remain realistic outcomes.

Root Cause Analysis

The vulnerability stems from:

Improper synchronization between metadata pre-buffering threads
Insufficient validation of variadic buffer offsets and lengths
Incorrect lifetime management of internal buffer objects
Lack of test coverage for pre-buffering execution paths

The fix includes:

Strengthened buffer validation logic
Corrected pre-buffering handling for variadic buffers and dictionaries
Additional test coverage
Sanitizer (ASAN/UBSAN) regression tests

Attack Preconditions

Exploitation requires all of the following:

A native C++ application linking Apache Arrow C++
Explicit enabling of PreBufferMetadata
Ingestion of attacker-controlled IPC files
Specific buffer layouts triggering race conditions

Because pre-buffering is disabled by default and not exposed in common bindings, the attack surface is limited to custom C++ implementations.

Exploitation Scenarios (Educational)

For educational awareness:

An attacker would need to craft a malicious Arrow IPC file containing carefully structured variable-length buffers. The goal would be to manipulate metadata ordering and buffer offsets such that during pre-buffering:

Memory gets allocated
Freed prematurely under concurrent access
A shared pointer write occurs after free

Realistic outcomes:

Immediate segmentation fault
Heap corruption
Crash during batch file processing
Service restart loop

Reliable code execution would require:

Precise heap grooming
Deterministic thread scheduling
Memory layout predictability

Such conditions are highly unstable in modern systems with ASLR and hardened allocators.

No public proof-of-concept exploit has been observed. No known exploitation has been reported in the wild.

Impact Assessment

Availability Impact

High – Service crash or repeated termination possible

Integrity Impact

Low to Moderate – Memory corruption possible

Confidentiality Impact

Low – No direct data disclosure vector identified

Indicators of Compromise

Sudden segmentation faults during IPC file ingestion
Crashes referencing arrow::ipc::RecordBatchFileReader
Unexpected termination while reading Arrow IPC files
Repeated service restarts under load
Core dumps showing heap corruption

Detection and Monitoring

1. Application Crash Detection (Linux)

Monitor syslog or journald:

journalctl -xe | grep -E "segfault|arrow|RecordBatchFileReader"

Alert on repeated crashes of processes linked against libarrow.

2. Core Dump Analysis

Search stack traces for:

arrow::ipc::RecordBatchFileReader
PreBufferMetadata
Buffer

If AddressSanitizer is enabled, look for:

heap-use-after-free

3. Splunk Query – Crash Monitoring

index=os_logs ("segfault" OR "core dumped" OR "aborted")
| search process_name="your_app_name"
| search stack_trace="arrow::ipc" OR stack_trace="RecordBatchFileReader"
| stats count by host, process_name

4. ELK / OpenSearch Query

{
  "query": {
    "bool": {
      "must": [
        { "match": { "message": "segfault" } },
        { "match": { "message": "arrow::ipc" } }
      ]
    }
  }
}

5. Runtime Dependency Check

Identify vulnerable versions:

strings /usr/lib/libarrow.so | grep "Apache Arrow"

ldd your_application_binary | grep arrow

Any version between 15.0.0 and 23.0.0 should be considered vulnerable.

6. Build-Time Source Code Audit

Search for usage of:

RecordBatchFileReader::PreBufferMetadata

If found, system should be prioritized for upgrade.

Log Sources to Monitor

Application logs
Linux syslog / journald
Windows Event Viewer (Application logs)
Crash reporting systems
CI/CD build logs
Container runtime logs
Kubernetes pod restart events
EDR telemetry

MITRE ATT&CK Mapping

CWE-416 – Use After Free
T1499 – Endpoint Denial of Service
T1203 – Exploitation for Client Execution (if malicious file ingestion scenario applies)

Defensive Recommendations

Upgrade immediately to Apache Arrow 23.0.1 or later.
If upgrade is delayed, disable metadata pre-buffering.
Avoid ingesting IPC files from untrusted sources.
Enable compiler sanitizers during testing.
Deploy heap hardening where possible.
Monitor crash frequency after file ingestion events.

Safe Testing Guidance

To validate exposure in a controlled lab:

Build application with AddressSanitizer enabled
Enable metadata pre-buffering intentionally
Run fuzz testing against IPC file ingestion
Monitor for heap-use-after-free reports

Testing should only be conducted in isolated environments. Production systems should not be used for vulnerability validation.

Risk Evaluation Summary

Factor	Assessment
Attack Complexity	High
Required Privileges	None
User Interaction	None
Default Exposure	Low
Real-World Exploit Likelihood	Low to Moderate (DoS focused)

Conclusion

CVE-2026-25087 represents a classic use-after-free condition in Apache Arrow C++ under a specific configuration involving metadata pre-buffering. While the practical exploitation window is narrow and mostly limited to denial-of-service outcomes, the memory corruption risk warrants immediate remediation in affected environments.

Organizations using Arrow C++ directly should verify configuration settings and upgrade without delay. Systems not explicitly enabling metadata pre-buffering are unlikely to be impacted but should still confirm version exposure.

Upgrading to version 23.0.1 fully resolves the issue.