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.
History

Fri, 13 Feb 2026 19:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Fri, 13 Feb 2026 18:15:00 +0000

Type Values Removed Values Added
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.
Title The BACnet Protocol Stack library has an Off-by-one Stack-based Buffer Overflow in tokenizer_string
Weaknesses CWE-193
References
Metrics cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-02-13T18:19:36.183Z

Reserved: 2026-01-05T16:44:16.368Z

Link: CVE-2026-21870

cve-icon Vulnrichment

Updated: 2026-02-13T18:19:31.816Z

cve-icon NVD

Status : Received

Published: 2026-02-13T18:16:19.783

Modified: 2026-02-13T18:16:19.783

Link: CVE-2026-21870

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.