cvedb.io
CVE-2026-21870
MEDIUM · CVSS 5.5
EPSS exploitation probability: 0%
Published 2026-02-13T18:16:19.783 · Last modified 2026-06-17T10:19:03.763

Summary

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.

Affected products

bacnetstack — bacnet_stack

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.