CVE-2026-48141 Overview
CVE-2026-48141 is a memory leak vulnerability in National Instruments (NI) grpc-device server affecting the BeginSidebandStream function. The flaw allows an authenticated network attacker to exhaust server memory, leading to denial of service. NI grpc-device version 2.17.0 and prior releases are affected, along with NI InstrumentStudio 2026 Q1 and Q2. The weakness is classified as [CWE-401] Missing Release of Memory after Effective Lifetime. While exploitation requires low privileges and high attack complexity, successful abuse degrades availability of test and measurement infrastructure that relies on the gRPC device service.
Critical Impact
Repeated invocation of BeginSidebandStream leaks server memory and can exhaust resources, rendering the NI grpc-device server unresponsive to legitimate instrumentation traffic.
Affected Products
- NI grpc-device server versions 2.17.0 and prior
- NI InstrumentStudio 2026 Q1
- NI InstrumentStudio 2026 Q2
Discovery Timeline
- 2026-06-19 - CVE-2026-48141 published to NVD
- 2026-06-25 - Last updated in NVD database
Technical Details for CVE-2026-48141
Vulnerability Analysis
The vulnerability resides in the BeginSidebandStream remote procedure call (RPC) exposed by the NI grpc-device server. This RPC initiates a sideband data channel used to stream high-throughput instrument data outside the primary gRPC stream. Each invocation allocates server-side resources to track the new sideband session. The implementation fails to release those resources under specific conditions, leaving allocations referenced but unused after the session ends or fails to establish.
An attacker with authenticated network access can issue repeated BeginSidebandStream calls. Each call increments the resident memory footprint of the server process. Over time, the cumulative leak exhausts available memory on the host, causing the service or the underlying operating system to terminate or stall. Because the NI grpc-device server typically fronts physical test instruments, the impact extends to any automated test workflows or InstrumentStudio sessions that depend on the affected service.
Root Cause
The defect is a classic [CWE-401] Missing Release of Memory after Effective Lifetime. The BeginSidebandStream code path allocates session tracking structures without a corresponding deallocation under all exit conditions. The cleanup logic does not consistently free buffers when streams are abandoned, fail handshake, or are torn down by the client.
Attack Vector
Exploitation is network-based and requires valid credentials to reach the gRPC endpoint. An attacker scripts repeated calls to BeginSidebandStream, optionally aborting each session immediately to maximize the rate of leaked allocations. No user interaction is required. The vulnerability does not expose data or allow code execution; impact is limited to availability of the grpc-device service and any dependent instrumentation workflows. Refer to the GitHub Security Advisory GHSA-j4qc-5v3f-rf87 for vendor technical details.
Detection Methods for CVE-2026-48141
Indicators of Compromise
- Sustained growth of resident memory in the NI grpc-device server process without a corresponding increase in legitimate instrument session count.
- High volume of BeginSidebandStream RPC requests originating from a single authenticated client or short-lived connections.
- Service crashes, out-of-memory (OOM) events, or operating system kills targeting the grpc-device server process.
Detection Strategies
- Instrument the grpc-device host with process memory telemetry and alert on monotonic growth exceeding baseline over multi-hour windows.
- Enable gRPC server access logging and aggregate counts of BeginSidebandStream calls per authenticated principal to identify abusive patterns.
- Correlate authentication logs with RPC call rates to detect credential misuse against the grpc-device service.
Monitoring Recommendations
- Track host-level memory pressure and OOM killer events on systems running NI grpc-device or InstrumentStudio backend services.
- Apply rate-limiting or anomaly detection to gRPC method invocations, with thresholds tuned for BeginSidebandStream traffic.
- Forward gRPC server logs and host metrics to a centralized analytics platform for retention and longitudinal analysis.
How to Mitigate CVE-2026-48141
Immediate Actions Required
- Inventory all systems running NI grpc-device server 2.17.0 or earlier and NI InstrumentStudio 2026 Q1 or Q2.
- Apply the fixed release published by NI as referenced in the NI Critical Security Update advisory.
- Restrict network access to the grpc-device gRPC endpoint to trusted measurement subnets only.
Patch Information
NI has published fixes through the GitHub Security Advisory GHSA-j4qc-5v3f-rf87 and the corresponding NI security update bulletin. Upgrade NI grpc-device to a release newer than 2.17.0 and update InstrumentStudio to a build that ships the patched server component.
Workarounds
- Place the grpc-device server behind a firewall or VPN that limits access to authenticated test automation hosts.
- Schedule periodic restarts of the grpc-device service to reclaim leaked memory until the patch can be applied.
- Revoke or rotate credentials for any service accounts that authenticate to the grpc-device endpoint and are no longer required.
# Configuration example: restrict access to the grpc-device port using firewalld
# Replace 31763 with the actual port used by your deployment
sudo firewall-cmd --permanent --zone=internal --add-source=10.20.30.0/24
sudo firewall-cmd --permanent --zone=internal --add-port=31763/tcp
sudo firewall-cmd --permanent --zone=public --remove-port=31763/tcp
sudo firewall-cmd --reload
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
