Iterator Vulnerability in MCUboot Affecting TLV Parsing by MCU Tools

CVE-2026-127915

What is CVE-2026-127915?

The MCUboot TLV iterator contains a flaw in its method for walking through image trailer TLVs, where it fails to properly validate the length of entries. This allows attackers to exploit the 'it_len' field, which can lead to reading beyond the allocated TLV area. Even though there are safeguards limiting the impact of this vulnerability during pre-authentication processes, concerns remain if non-default configurations are utilized, such as the MCUBOOT_RAM_LOAD setting, which could introduce unchecked memory operations. The recommended fix involves ensuring that all entries are validated against the maximum boundary defined by the TLV area.

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