Vulnerability in Bacnet-stack
CVE-2026-21870
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 ca…
EPSS: 0.002 (15.2th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.
Affected products
- Bacnet-stack — versions <= 1.4.2, >= 1.5.0.rc1, <= 1.5.0.rc2
- Bacnetstack Bacnet_stack — versions 1.5.0
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Exploit, Vendor Advisory)
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (Patch, x_refsource_MISC)
Frequently asked questions
- What is CVE-2026-21870?
- CVE-2026-21870 is a medium-severity vulnerability in Bacnet-stack, classified under Off-by-one Error. CVSS score: 5.5/10. Published 2026-02-13.
- How severe is CVE-2026-21870?
- Medium severity. CVSS v3 base score is 5.5 out of 10.