CVE-2026-44630: Apache IoTDB RPC Service DoS Vulnerability

CVE-2026-44630 Overview

CVE-2026-44630 is a denial-of-service vulnerability in the Apache IoTDB Remote Procedure Call (RPC) service. The flaw stems from improper validation of length fields in Thrift frames received by the service. A remote unauthenticated attacker can send a crafted malformed Thrift frame that forces IoTDB to allocate excessive memory. The process then crashes with an OutOfMemoryError, terminating database availability.

The issue affects Apache IoTDB versions before 1.3.8 and versions from 2.0.0 before 2.0.9. The Apache IoTDB project has published fixed release 2.0.10. The vulnerability is classified under CWE-400: Uncontrolled Resource Consumption.

Critical Impact
A single crafted Thrift frame from an unauthenticated network attacker can crash the IoTDB server, causing complete loss of availability for time-series data workloads.

Affected Products

Apache IoTDB versions prior to 1.3.8
Apache IoTDB versions 2.0.0 through 2.0.8
Apache IoTDB deployments exposing the RPC/Thrift service on the network

Discovery Timeline

2026-08-10 - CVE-2026-44630 published to NVD
2026-08-12 - Last updated in NVD database

Technical Details for CVE-2026-44630

Vulnerability Analysis

Apache IoTDB exposes an RPC service built on Apache Thrift for client communication. Thrift framed transport prefixes each message with a 4-byte length field indicating the size of the payload that follows. The IoTDB RPC handler reads this length value and pre-allocates a buffer of the declared size before reading the actual payload.

The handler does not sanity-check the declared length against a reasonable upper bound or against the amount of data actually available on the socket. An attacker who can reach the RPC port can send a frame that declares an enormous payload length while providing little or no payload data.

The Java Virtual Machine attempts to allocate the requested buffer on the heap. When the requested size exceeds available heap capacity, the allocation triggers a java.lang.OutOfMemoryError. This error terminates the IoTDB process and disrupts all connected clients and ingestion pipelines.

Root Cause

The root cause is missing bounds validation on attacker-controlled length fields in the Thrift framed transport parser. The RPC service trusts the length prefix and delegates buffer allocation to the underlying Thrift library without enforcing a maximum frame size configured for the deployment.

Attack Vector

Exploitation requires only network access to the IoTDB RPC port. No authentication, user interaction, or prior foothold is required. An attacker crafts a Thrift frame with a length header set to a very large value, for example approaching the maximum 32-bit signed integer, then closes or stalls the connection. The server attempts the allocation and crashes. Repeated frames can prevent the service from staying online after restart.

No verified public proof-of-concept exploit code is currently referenced in the advisory. See the Apache mailing list thread and the OpenWall OSS-Security discussion for the coordinated disclosure details.

Detection Methods for CVE-2026-44630

Indicators of Compromise

Unexpected java.lang.OutOfMemoryError entries in IoTDB server logs correlated with inbound RPC connections
Abrupt IoTDB process termination or restart loops without corresponding administrative action
Inbound TCP sessions to the IoTDB RPC port that transmit only a small header before disconnecting
Sudden spikes in JVM heap utilization on IoTDB nodes with no matching legitimate query workload

Detection Strategies

Monitor JVM garbage collection and heap metrics for anomalous allocation spikes tied to RPC listener threads
Alert on repeated IoTDB process restarts and correlate with source IP addresses seen in connection logs
Inspect network flow telemetry for short-lived connections to the IoTDB RPC port that transfer only a handful of bytes
Deploy Thrift-aware network intrusion detection signatures that flag framed transport headers declaring implausibly large payload sizes

Monitoring Recommendations

Enable verbose logging on the IoTDB RPC service and forward logs to a centralized analytics platform for correlation
Track the count of OutOfMemoryError events per node as a service-health indicator and alert on any non-zero value
Baseline normal Thrift frame sizes in production traffic and alert on frames exceeding the baseline by an order of magnitude
Correlate database availability alerts with authentication and network telemetry to distinguish DoS attempts from operational faults

How to Mitigate CVE-2026-44630

Immediate Actions Required

Upgrade Apache IoTDB to version 2.0.10, which contains the vendor fix
For deployments on the 1.x branch, upgrade to version 1.3.8 or later
Restrict network exposure of the IoTDB RPC port to trusted client subnets using firewall rules or security groups
Inventory all IoTDB nodes and identify any instance reachable from untrusted networks for priority remediation

Patch Information

The Apache IoTDB project recommends upgrading to version 2.0.10, which enforces validation on Thrift frame length fields and prevents unbounded buffer allocation. Users on the 1.x line should move to 1.3.8. Refer to the Apache mailing list thread for the official announcement and release notes.

Workarounds

Place the IoTDB RPC endpoint behind a network proxy or firewall that enforces a maximum request size below the JVM heap allocation limit
Configure the JVM with conservative heap sizing and enable automatic service restart to reduce downtime while patching is scheduled
Restrict RPC access to authenticated client networks using mutual TLS or IP allowlisting where the deployment supports it
Rate-limit new inbound connections to the RPC port at the network layer to slow repeat DoS attempts

bash

# Example iptables rule limiting new connections to the IoTDB RPC port (default 6667)
iptables -A INPUT -p tcp --dport 6667 -m conntrack --ctstate NEW \
  -m limit --limit 20/minute --limit-burst 40 -j ACCEPT
iptables -A INPUT -p tcp --dport 6667 -m conntrack --ctstate NEW -j DROP