CVE-2026-67976 Overview
CVE-2026-67976 is a denial of service vulnerability in the Ref::SignalGen component of the fprime framework v4.2.2. The component fails to validate the safety of user-controlled parameters. Attackers can supply unsafe input values to trigger resource exhaustion and disrupt availability of the affected service. The vulnerability is classified under CWE-400 (Uncontrolled Resource Consumption). fprime is an open-source flight software framework maintained by NASA and used in embedded and spaceflight applications.
Critical Impact
Remote, unauthenticated attackers can trigger denial of service against fprime deployments by sending unsafe parameter values to the Ref::SignalGen component.
Affected Products
- fprime framework v4.2.2
- Deployments including the Ref::SignalGen reference component
- Downstream projects built on the affected fprime release
Discovery Timeline
- 2026-08-03 - CVE-2026-67976 published to NVD
- 2026-08-05 - Last updated in NVD database
Technical Details for CVE-2026-67976
Vulnerability Analysis
The Ref::SignalGen component in fprime v4.2.2 accepts parameters that control signal generation behavior. The component does not validate the safety or bounds of these user-controlled parameters before processing them. Supplying malformed or excessive parameter values causes uncontrolled resource consumption, leading to denial of service of the affected process. Because fprime is deployed in embedded, mission-critical, and spaceflight contexts, availability loss in a signal generation component can propagate to dependent tasks and telemetry pipelines.
Root Cause
The root cause is missing input validation on parameters accepted by Ref::SignalGen. The component trusts caller-supplied values without enforcing safe ranges, types, or resource ceilings. This maps directly to CWE-400, Uncontrolled Resource Consumption.
Attack Vector
The vulnerability is exploitable over the network without authentication or user interaction. An attacker with the ability to reach the command interface of an fprime deployment can submit unsafe parameter values to Ref::SignalGen to trigger the denial of service. Confidentiality and integrity are not impacted; only availability is affected.
No verified public exploit code is available for this vulnerability. Technical discussion is tracked in the GitHub CVE Issue Discussion and the GitHub FPrime Repository.
Detection Methods for CVE-2026-67976
Indicators of Compromise
- Unexpected termination, hangs, or restarts of processes hosting the Ref::SignalGen component
- Command dispatches to Ref::SignalGen containing out-of-range or malformed parameter values
- Sudden CPU or memory spikes correlated with signal generator command traffic
Detection Strategies
- Instrument the fprime command dispatcher to log parameter values received by Ref::SignalGen and alert on values outside expected operational ranges.
- Baseline normal command rates and parameter distributions for reference components, then flag statistical outliers.
- Correlate process crash events with preceding command telemetry to identify parameter-triggered failures.
Monitoring Recommendations
- Monitor host telemetry for abnormal CPU, memory, and thread counts on systems running fprime deployments.
- Track command uplink logs for repeated invocations of Ref::SignalGen from a single source.
- Forward fprime process supervisor logs to a central SIEM for correlation with network-side command sources.
How to Mitigate CVE-2026-67976
Immediate Actions Required
- Restrict network reachability to fprime command interfaces so only trusted ground stations or operators can dispatch commands.
- Audit deployments for inclusion of the Ref::SignalGen reference component and remove it from production builds where not required.
- Add wrapper validation around Ref::SignalGen parameter handlers to reject unsafe input before it reaches the component logic.
Patch Information
No fixed version was listed in the NVD entry at the time of publication. Monitor the GitHub FPrime Repository for upstream commits that add parameter validation to Ref::SignalGen, and track the GitHub CVE Issue Discussion for remediation status.
Workarounds
- Remove or disable the Ref::SignalGen component in deployments that do not require it, since it ships as a reference example.
- Enforce parameter allow-lists at the command dispatch layer to constrain inputs to known-safe ranges.
- Place fprime command endpoints behind authenticated, network-segmented links to prevent unauthenticated remote access.
# Configuration example: restrict command interface access with iptables
iptables -A INPUT -p tcp --dport 50000 -s 10.0.0.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 50000 -j DROP
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
