EUVD-2026-61175

The Sierra Wireless HL7800 cellular modem driver drivers/modem/vendorstandalone/hl7800.c, located at drivers/modem/hl7800.c in v4.4.0 and earlier parses AT responses with roughly twenty handlers that call netbuflinearizevalue, sizeofvalue, buf, 0, len into a 128-byte stack buffer and then write...

CVE-2026-12520

In Zephyr RTOS v4.4.0 and earlier, the HL7800 modem driver's ~20 AT-response handlers write into a 128-byte stack buffer. The +KCELLMEAS handler passes the unbounded wire length as destination size, causing a full stack overflow; other handlers suffer single-byte off-by-one NUL writes. The fix us...