CVE-2026-21870 - The BACnet Protocol Stack library has an Off-by-one Stack-based Buffer Overflow ...

CVE ID : CVE-2026-21870 Published : Feb. 13, 2026, 6:16 p.m. | 17 minutes ago Description : BACnet Protocol Stack library provides a BACnet application layer, network layer and media access (MAC) layer communications services. In 1.4.2, 1.5.0.rc2, and earlier, an off-by-one stack-based buffer overflow in the ubasic interpreter causes a crash (SIGABRT) when processing string literals longer than the buffer limit. The tokenizer_string function in src/bacnet/basic/program/ubasic/tokenizer.c incorrectly handles null termination for maximum-length strings. It writes a null byte to dest[40] when the buffer size is only 40 (indices 0-39), triggering a stack overflow. Severity: 5.5 | MEDIUM Visit the link for more details, such as CVSS details, affected products, timeline, and more...