CVE-2026-21870

MEDIUM

5.5

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.

Details CVE

Score CVSS v3.15.5

SeveriteMEDIUM

Vecteur CVSSCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

Vecteur d'attaqueLOCAL

ComplexiteLOW

Privileges requisNONE

Interaction utilisateurREQUIRED

Publie2/13/2026

Derniere modification2/18/2026

Sourcenvd

Observations honeypot0

Produits affectes

bacnetstack:bacnet_stack

Faiblesses (CWE)

CWE-193

References

https://github.com/bacnet-stack/bacnet-stack/commit/4e1176394a5ae50d2fd0b5790d9bff806dc08465(security-advisories@github.com)

https://github.com/bacnet-stack/bacnet-stack/pull/1196(security-advisories@github.com)

https://github.com/bacnet-stack/bacnet-stack/security/advisories/GHSA-pc83-wp6w-93mx(security-advisories@github.com)

Correlations IOC

Aucune correlation enregistree

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