CVE-2026-6232 in LR1110 Transceiver
Summary
by MITRE • 10/12/2026
An out-of-bounds write vulnerability in the SPI host command interface of Semtech's LR11xx transceiver firmware where a crafted SPI host command with an oversized length field can cause the firmware to write up to 254 arbitrary bytes past the bounds of an internal, non-persistent memory buffer. Exploitation requires physical access to the device and logical access to the SPI bus.
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Analysis
by VulDB Data Team • 10/12/2026
The vulnerability identified in Semtech's LR11xx transceiver firmware represents a critical out-of-bounds write condition within the Serial Peripheral Interface host command interface. This flaw stems from insufficient validation of input parameters, specifically regarding the length field associated with SPI commands sent to the device. When an attacker provides a crafted SPI command containing an oversized length value that exceeds the allocated size of internal memory buffers, the firmware fails to perform adequate bounds checking before initiating data transfer operations. Consequently, this allows for the writing of up to 254 arbitrary bytes beyond the boundaries of non-persistent memory structures. The nature of this vulnerability classifies it under CWE-787: Out-of-bounds Write, which is widely recognized as a severe integrity violation that can lead to system instability or complete compromise depending on the memory layout and execution context.
The operational impact of exploiting this flaw extends beyond simple data corruption due to its potential for code execution. By carefully crafting the payload written past the buffer boundary, an attacker may overwrite adjacent memory regions containing critical control data such as return addresses, function pointers, or security flags stored in volatile RAM. This capability effectively enables arbitrary code execution on the microcontroller hosting the transceiver firmware. Given that these devices are often integral components of IoT ecosystems and wireless communication systems, successful exploitation could allow an adversary to intercept communications, inject malicious commands into network traffic, or pivot further into connected networks if the device serves as a gateway or bridge. The non-persistent nature of the affected memory implies that while the immediate effects may be reset upon power cycling, repeated exploitation can establish persistent backdoors through other means such as modifying flash storage via subsequent privileged operations facilitated by the initial compromise.
Exploitation constraints significantly influence the risk profile and remediation strategy for this vulnerability. Physical access to the device is a mandatory prerequisite, meaning remote attackers cannot leverage this flaw directly over network interfaces unless they have already compromised adjacent systems with physical connectivity capabilities. Furthermore, logical access to the SPI bus is required, which typically involves soldering probes or utilizing debug headers like SWD or JTAG if not properly secured by fuse bits or security configurations. This restriction limits the attack surface primarily to scenarios involving device manufacturing, maintenance, testing environments, or physically accessible IoT deployments where perimeter defenses have been breached. Despite these constraints, the severity remains high because physical access often correlates with higher levels of trust and reduced monitoring compared to remote vectors.
Mitigation strategies must address both software defects and hardware security configurations. Semtech should release a firmware update that implements strict validation checks on all SPI command length fields before processing them against internal buffers. This includes ensuring that the requested transfer size does not exceed the allocated buffer capacity and implementing safeguards such as stack canaries or memory protection units if supported by the underlying architecture to detect and halt out-of-bounds writes at runtime. For system integrators, immediate mitigation involves disabling unused debug interfaces like SWD/JTAG through hardware fuse settings to prevent logical access to the SPI bus from external tools. Additionally, employing secure boot mechanisms ensures that only signed firmware versions are executed, reducing the window of opportunity for attackers exploiting unpatched vulnerabilities during device lifecycle phases where updates might be delayed or unavailable. Regular security audits and static analysis scanning focused on embedded C code can help identify similar buffer handling issues before deployment in production environments aligned with industry standards such as OWASP IoT Top Ten which emphasizes secure configuration and robust input validation principles.