CVE-2026-26742 in Autopilot
Summary
by MITRE • 03/10/2026
PX4 Autopilot versions 1.12.x through 1.15.x contain a protection mechanism failure in the "Re-arm Grace Period" logic. The system incorrectly applies the in-air emergency re-arm logic to ground scenarios. If a pilot switches to Manual mode and re-arms within 5 seconds (default configuration) of an automatic landing, the system bypasses all pre-flight safety checks, including the throttle threshold check. This allows for an immediate high-thrust takeoff if the throttle stick is raised, leading to loss of control.
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Analysis
by VulDB Data Team • 03/14/2026
The vulnerability identified as CVE-2026-26742 represents a critical protection mechanism failure within the PX4 Autopilot software ecosystem affecting versions 1.12.x through 1.15.x. This flaw exists within the Re-arm Grace Period logic implementation where the system fails to properly distinguish between airborne and ground operational contexts. The protection mechanism is designed to prevent unauthorized re-arming during flight operations, but the logic error causes the system to incorrectly apply in-air emergency re-arm procedures to ground-based scenarios, fundamentally undermining the safety protocols that govern autonomous flight operations.
The technical flaw manifests when a pilot transitions to Manual mode and subsequently re-arms the system within the default 5-second grace period following an automatic landing event. Under normal operational conditions, the autopilot should enforce strict pre-flight safety protocols including throttle threshold validation before permitting re-arming. However, this vulnerability allows the system to bypass these critical safety checks, creating a scenario where the aircraft can be immediately re-armed without proper validation. The bypass occurs specifically during the transition period between automatic landing completion and manual re-arming, where the system's state detection mechanism fails to properly identify the ground-based operational context.
The operational impact of this vulnerability is severe and potentially catastrophic for unmanned aerial vehicle operations. When the throttle stick is raised following the bypassed re-arming process, the system permits immediate high-thrust takeoff without the normal safety constraints that would typically prevent such rapid escalation. This creates an immediate risk of loss of control as the aircraft transitions from a controlled landing state to an unvalidated high-thrust takeoff scenario. The vulnerability essentially removes the critical safety buffer that would normally prevent rapid, uncontrolled acceleration, potentially leading to aircraft crashes or loss of ground control. The risk is particularly elevated in environments where precise control and predictable aircraft behavior are essential for safe operation.
From a cybersecurity perspective, this vulnerability aligns with CWE-284 Access Control Issues and represents a failure in the principle of least privilege within autonomous flight systems. The flaw demonstrates inadequate state management and context awareness in the autopilot's safety logic, creating an attack surface where unauthorized system re-arming can occur without proper validation. This vulnerability also maps to ATT&CK technique T1543.003 Create or Modify System Process for the purpose of bypassing safety mechanisms and T1070.006 Indicator Removal on Host for potentially hiding the unauthorized re-arming activity. The security implications extend beyond immediate operational risks to include potential exploitation by malicious actors who could leverage this bypass to gain unauthorized control over aircraft systems.
Mitigation strategies for this vulnerability should focus on immediate software patches that correct the Re-arm Grace Period logic to properly distinguish between ground and airborne operational contexts. System administrators should implement immediate operational procedures that require manual confirmation of re-arming procedures and verify system status before allowing high-thrust operations. The recommended approach includes enhancing state detection mechanisms to properly validate aircraft position and operational context before permitting re-arming, implementing additional validation checks that cannot be bypassed during the grace period, and establishing operational protocols that prevent re-arming in ground scenarios without explicit manual override confirmation. Additionally, system monitoring should be enhanced to detect and alert on unauthorized re-arming events that bypass normal safety protocols, ensuring that operators are immediately notified of potential security breaches or system malfunctions.