CVE-2026-48139 Overview
CVE-2026-48139 is a NULL pointer dereference vulnerability [CWE-476] in the National Instruments (NI) grpc-device server, specifically in the data moniker service. An unauthenticated remote attacker can crash the service by submitting an unknown value to the data moniker service, resulting in a denial of service. The flaw affects NI grpc-device version 2.17.0 and prior, and is also exposed through NI InstrumentStudio releases that bundle the vulnerable server component.
No authentication or user interaction is required to trigger the crash, and the attack is reachable over the network wherever the gRPC service is exposed.
Critical Impact
A single malformed gRPC request can crash the NI grpc-device server, disrupting instrument control and automated test workflows that depend on it.
Affected Products
- NI grpc-device server version 2.17.0 and prior
- NI InstrumentStudio 2026 Q1
- NI InstrumentStudio 2026 Q2
Discovery Timeline
- 2026-06-19 - CVE-2026-48139 published to NVD
- 2026-06-25 - Last updated in NVD database
Technical Details for CVE-2026-48139
Vulnerability Analysis
The NI grpc-device project exposes National Instruments hardware drivers through a gRPC interface, allowing remote clients to control test and measurement instruments. The data moniker service within this server provides a streaming abstraction for reading from and writing to instrument data sources.
The service processes moniker identifiers supplied by clients and dispatches them to internal handlers. When a client supplies an unknown moniker value, the service fails to validate the lookup result before dereferencing the returned pointer. The dereference of the NULL pointer terminates the server process and disrupts every connected client session.
Because the attack vector is network-based and requires no privileges or user interaction, any reachable instance of the service is vulnerable to remote denial of service.
Root Cause
The root cause is a missing NULL check on a pointer returned by a moniker lookup in the data moniker service [CWE-476]. The code path assumes the lookup succeeds for any client-supplied identifier and proceeds to dereference the pointer to invoke a handler. An unknown value causes the lookup to return NULL, and the subsequent dereference triggers a segmentation fault that takes down the server process.
Attack Vector
An unauthenticated attacker with network access to the grpc-device server sends a crafted gRPC request to the data moniker service containing an unrecognized moniker value. The server attempts to resolve the value, receives a NULL result, and crashes when it dereferences the pointer. The vulnerability is described in the NI grpc-device security advisory GHSA-7vg9-5c74-289x and the NI Security Update Notification.
No public proof-of-concept is available at the time of writing, and the vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog.
Detection Methods for CVE-2026-48139
Indicators of Compromise
- Unexpected termination or repeated restarts of the ni_grpc_device_server process on hosts running NI grpc-device or InstrumentStudio.
- gRPC connection resets or UNAVAILABLE status codes returned to clients of the data moniker service immediately after specific requests.
- Operating system crash dumps or Windows Application event logs showing access violation faults in the grpc-device server binary.
Detection Strategies
- Monitor process lifecycle events for ni_grpc_device_server and alert on abnormal exit codes or rapid restart loops.
- Inspect gRPC traffic to the data moniker service for requests containing moniker identifiers that do not match the application's expected allowlist.
- Correlate server crashes with inbound network connections from unexpected sources to identify probing or exploitation attempts.
Monitoring Recommendations
- Forward host event logs and process telemetry from systems running NI grpc-device into a centralized analytics platform for long-term correlation.
- Track network exposure of the gRPC listener port and alert when the service becomes reachable from untrusted network segments.
- Baseline normal moniker traffic patterns from authorized test clients so that anomalous request volumes or unknown identifiers are flagged.
How to Mitigate CVE-2026-48139
Immediate Actions Required
- Upgrade NI grpc-device to a version later than 2.17.0 as published in the NI grpc-device security advisory GHSA-7vg9-5c74-289x.
- Update NI InstrumentStudio installations from 2026 Q1 and 2026 Q2 to the patched release referenced in the NI Security Update Notification.
- Restrict network access to the grpc-device listener port to known test automation hosts using host or network firewall rules.
Patch Information
NI has published fixes through its 2026 security update bulletin for grpc-device server. Administrators should review the vendor advisory, confirm the fixed version, and apply it to all systems running grpc-device standalone or bundled with InstrumentStudio 2026 Q1 and 2026 Q2.
Workarounds
- Isolate the grpc-device server on a dedicated management network and block inbound access from general-purpose user or guest networks.
- Disable the grpc-device server on hosts where remote instrument control over gRPC is not required.
- Place an authenticating reverse proxy in front of the gRPC endpoint to limit exposure to authorized clients until the patch is deployed.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
