CVE-2026-67974 Overview
CVE-2026-67974 is a parser boundary flaw in the Software Bus Network (SBN) application within NASA's Core Flight System (cFS) version 7.0.1. The vulnerability resides in the peer subscription message handling logic. An attacker can send a crafted network packet to trigger a Denial of Service (DoS) condition against the affected cFS instance.
The cFS framework provides reusable flight software for spacecraft and embedded mission systems. The SBN application extends the internal Software Bus across networked nodes, making it a network-exposed component. A successful attack disrupts message processing between peers.
Critical Impact
A remote attacker can crash or destabilize cFS-based flight software by sending a single malformed SBN peer subscription message, disrupting inter-node communication.
Affected Products
- NASA Core Flight System (cFS) version 7.0.1
- Software Bus Network (SBN) application shipped with cFS v7.0.1
- Downstream mission software that integrates the affected SBN release
Discovery Timeline
- 2026-08-03 - CVE-2026-67974 published to NVD
- 2026-08-03 - Last updated in NVD database
Technical Details for CVE-2026-67974
Vulnerability Analysis
The flaw exists in how the SBN application parses peer subscription messages received from remote nodes. The parser fails to enforce correct boundary checks on incoming message fields. When a crafted packet is processed, the parser reads or acts on data outside the intended message structure.
The result is an abnormal termination or hang of the SBN process. Because SBN mediates cross-node Software Bus traffic, its failure interrupts telemetry and command message flow between cFS applications on different peers. The issue is tracked publicly in the project repository at GitHub Issue #1074.
Root Cause
The root cause is missing or insufficient boundary validation in the SBN peer subscription message handler. The handler assumes input conforms to expected size and structure constraints. Malformed length or count fields in the subscription payload are not rejected before use.
Attack Vector
Exploitation requires network reachability to the SBN listener port used for peer communication. The attacker sends a single crafted subscription message that violates the expected parsing boundaries. No authentication mechanism is inherent to SBN peer traffic, so any host able to reach the port can deliver the payload.
No verified public exploit code is available. See the NASA cFS repository and the referenced issue for technical context on the affected code path.
Detection Methods for CVE-2026-67974
Indicators of Compromise
- Unexpected termination or restart of the SBN application process on cFS nodes
- Loss of Software Bus message flow between previously connected cFS peers
- Malformed or oversized subscription messages observed on SBN peer ports in packet captures
Detection Strategies
- Inspect network traffic to SBN peer ports for subscription messages with anomalous length fields or subscription counts
- Correlate SBN process crash events with inbound packets from non-allowlisted source addresses
- Enable verbose SBN protocol logging in test environments to fingerprint malformed peer message patterns
Monitoring Recommendations
- Alert on SBN process restarts and gaps in inter-peer heartbeat messages
- Baseline expected SBN peer IP addresses and flag connection attempts from unknown sources
- Capture and retain packet metadata for SBN peer traffic to support forensic reconstruction after an outage
How to Mitigate CVE-2026-67974
Immediate Actions Required
- Restrict network reachability of SBN peer ports to trusted mission network segments only
- Apply strict firewall or access control list rules allowing SBN peer traffic solely between known cFS nodes
- Monitor the NASA cFS repository and Issue #1074 for an official fix and integrate it once released
Patch Information
At the time of publication, no vendor patch reference is recorded in the NVD entry. Track the upstream project at the NASA cFS repository for a fix addressing the SBN peer subscription parser boundary check. Integrators should rebuild and redeploy mission images after the fix is merged and validated.
Workarounds
- Disable the SBN application on cFS nodes that do not require cross-node Software Bus communication
- Deploy a network filter or proxy in front of SBN peer ports to drop malformed subscription messages
- Isolate cFS deployments on segmented networks with no exposure to untrusted hosts
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
