CVE-2026-97692

HIGHCVSS 7.7/10

Last modified

CVE-2026-97692 is a high-severity vulnerability rated 7.7/10 on the CVSS scale. BACnet Stack is a BACnet open source protocol stack C library for embedded systems. Prior to versions 1.4.6, 1.5.2, and 1.6.1, the BACnet/SC message decoder walks the header-option list by following each option's MORE bit.

Description

BACnet Stack is a BACnet open source protocol stack C library for embedded systems. Prior to versions 1.4.6, 1.5.2, and 1.6.1, the BACnet/SC message decoder walks the header-option list by following each option's MORE bit. Nothing rejects a list whose last option still has the MORE bit set, and the decode walk has no upper bound on how many options it processes. A single crafted BVLC-SC frame makes the walk advance one option past the end of the message and read message[message_len], one byte out of bounds. When the bytes after the message carry more MORE-set option markers, the walk keeps going: it runs past the fixed 4-entry option array and writes decoded option fields out of bounds. On the server that decode array is the static global bsc_dm, so the out-of-bounds write lands in adjacent BSS. Both faults are reachable before authentication, from the first frame a peer sends on a BACnet/SC connection, and the bytes that follow the message are the same peer's prior-frame data. This issue has been patched in versions 1.4.6, 1.5.2, 1.6.1, and 1.7.0.

Metrics

Weakness Enumeration

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
bacnet-stackbacnet-stack< 1.4.6; >= 1.5.0, < 1.5.2; >= 1.6.0, < 1.6.1

References

Timeline

Published
Last Modified
Status
Awaiting Analysis

Frequently Asked Questions

What is CVE-2026-97692?
BACnet Stack is a BACnet open source protocol stack C library for embedded systems. Prior to versions 1.4.6, 1.5.2, and 1.6.1, the BACnet/SC message decoder walks the header-option list by following each option's MORE bit. Nothing rejects a list whose last option still has the MORE bit set, and the decode walk has no upper bound on how many options it processes. A single crafted BVLC-SC frame makes the walk advance one option past the end of the message and read message[message_len], one byte out of bounds. When the bytes after the message carry more MORE-set option markers, the walk keeps going: it runs past the fixed 4-entry option array and writes decoded option fields out of bounds. On the server that decode array is the static global bsc_dm, so the out-of-bounds write lands in adjacent BSS. Both faults are reachable before authentication, from the first frame a peer sends on a BACnet/SC connection, and the bytes that follow the message are the same peer's prior-frame data. This issue has been patched in versions 1.4.6, 1.5.2, 1.6.1, and 1.7.0.
How severe is CVE-2026-97692?
CVE-2026-97692 has a CVSS score of 7.7/10 (HIGH severity).
How do I fix CVE-2026-97692?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST