CVE-2026-92156 in F Prime
Summary
by MITRE • 10/14/2026
F´ (F Prime) is a framework that enables development and deployment of spaceflight and other embedded software applications. Prior to 4.3.0, Svc::EventManager loqQueue_internalInterfaceHandler packetization is vulnerable because EventManager accepts up to the framework LogBuffer maximum, but packet descriptor, event identifier, and time-tag metadata consume part of the larger ComBuffer and leave a smaller remaining budget for log arguments; serialization failure then reaches an assertion. When a deployment bridges events through GenericHub into EventManager and forwards a legal Fw::LogBuffer larger than EventManager remaining log-argument budget, under standard F Prime assertion handling, a legal bridged event payload aborts or resets the process, causing denial of service. This issue is fixed in version 4.3.0.
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Analysis
by VulDB Data Team • 10/14/2026
The vulnerability identified within the F Prime framework, specifically affecting versions prior to 4.3.0, centers on a critical logic error in the Svc::EventManager component responsible for handling log queue internal interface handlers and packetization. This issue arises from an incorrect calculation of available buffer space when processing incoming event data. The root cause lies in how the system allocates memory for different components of a log entry. While EventManager accepts packets up to the framework's maximum LogBuffer size, it fails to adequately account for the metadata overhead required by its own internal structures. Specifically, the packet descriptor, event identifier, and time-tag metadata consume space within the larger ComBuffer structure. This consumption reduces the remaining budget available for actual log arguments or payload data. Consequently, when a valid Fw::LogBuffer is received that exceeds this reduced effective capacity, the serialization process encounters an insufficient buffer condition.
Under standard operating conditions in embedded systems like those managed by F Prime, assertion failures are typically treated as fatal errors designed to prevent undefined behavior and facilitate debugging during development or early deployment phases. In this scenario, a legal bridged event payload triggers an assertion failure because the serialized data exceeds the calculated remaining log-argument budget. This results in an immediate abort or reset of the process running EventManager. Since F Prime is widely used for spaceflight and other critical embedded software applications where continuous operation is paramount, such abrupt terminations constitute a severe denial of service condition. The system does not gracefully handle the oversized payload but instead crashes, leading to potential loss of telemetry, control authority, or mission-critical data logging capabilities depending on which subsystem was affected by the reset.
This vulnerability can be categorized under CWE-20 Improper Input Validation and CWE-193 Off-by-One Error in terms of buffer management logic, although it is more accurately described as a logical miscalculation leading to resource exhaustion or assertion failure rather than a traditional memory corruption exploit. From an adversarial perspective, if an attacker can influence the content or routing of events through the GenericHub bridge into EventManager, they could potentially trigger this condition repeatedly to cause sustained denial of service against the flight software stack. This aligns with ATT&CK techniques related to Resource Hijacking and Service Availability impacts, particularly in environments where system stability is critical for mission success. The attack vector involves manipulating event streams that are bridged through GenericHub, requiring access to inject or modify these specific log events within the internal communication fabric of the embedded application.
The operational impact extends beyond simple process termination. In spaceflight applications, a reset may require re-initialization sequences that take significant time, during which no commands can be processed and no science data can be logged. This gap in coverage could lead to missed windows for critical operations or loss of valuable diagnostic information needed post-incident analysis. Furthermore, if the EventManager is part of a chain where other components depend on its continuous operation, the failure may cascade, affecting broader subsystem functionality. The reliance on assertions as crash mechanisms means that this behavior might be acceptable in development environments but becomes unacceptable and dangerous when deployed to operational hardware where graceful degradation or error recovery would be preferred over hard resets.
Mitigation for this vulnerability is straightforward and has already been implemented by the maintainers of the F Prime framework. Users running versions prior to 4.3.0 must upgrade to version 4.3.0 or later, which contains a fix that correctly accounts for metadata overhead when calculating available buffer space for log arguments. This ensures that serialization checks accurately reflect the true remaining capacity within the ComBuffer structure. For organizations unable to immediately patch their systems due to certification cycles or other constraints, temporary mitigations could include implementing stricter validation at the GenericHub bridge layer to drop any events whose total size exceeds a conservative threshold below the maximum LogBuffer limit. This proactive filtering prevents oversized payloads from ever reaching EventManager and triggering the assertion failure. Additionally, reviewing deployment configurations to ensure that event bridging does not inadvertently pass larger-than-intended log buffers can help reduce exposure until the patch is applied.