The Semtech LR11xx LoRa transceivers implement secure boot functionality using digital signatures to authenticate firmware. However, the implementation uses a non-standard cryptographic hashing algorithm that is vulnerable to second preimage attacks. An attacker with physical access to the device can exploit this weakness to generate a malicious firmware image with a hash collision, bypassing the secure boot verification mechanism and installing arbitrary unauthorized firmware on the device.
https://www.semtech.com/company/security/security-bulletins/sem-psa-2026-001
Published: 2026-04-07
Updated: 2026-04-08
Base Score: 6.8
Vector: CVSS2#AV:L/AC:L/Au:N/C:P/I:C/A:C
Severity: Medium
Base Score: 9.8
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Severity: Critical
Base Score: 7
Vector: CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:L/SI:L/SA:N
Severity: High
EPSS: 0.00015