Out-of-bounds Read in Bacnet-Stack

CVE-2026-41475

BACnet Stack is a BACnet open source protocol stack C library for embedded systems. Prior to 1.4.3, an out-of-bounds read vulnerability in bacnet-stack's WritePropertyMultiple service decoder allows unauthenticated remote attackers to read past allocated buffer boundaries by sending a truncated WPM request. The vulnerability stems from wpm_decode_object_property() calling the deprecated decode_tag_number_and_value() function, which performs no bounds checking on the input buffer. A crafted BACnet/IP packet with a truncated property payload causes the decoder to read 1-7 bytes past the end of the buffer, leading to crashes or information disclosure on embedded BACnet devices. This vulnerability is fixed in 1.4.3.

Vulnerability class: Buffer Overflow

EPSS: 0.005 (39.8th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-41475?
CVE-2026-41475 is a critical-severity vulnerability in Bacnet-Stack, classified under Out-of-bounds Read. CVSS score: 9.1/10. Published 2026-04-24.
How severe is CVE-2026-41475?
Critical severity. CVSS v3 base score is 9.1 out of 10.