CVE-2026-97692bacnet-stack out-of-bounds write
CVE-2026-97692 is a out-of-bounds write in bacnet-stack, rated high (7.7 on CVSS 3.1).
Why this priority: High severity, with no exploitation signal yet.
Published · Updated · NVD status: Received
What it is
Code writes past the end of a buffer, corrupting memory in ways an attacker can often turn into code execution.
How it is reached
An attacker can exploit it over the network, without an account, and nobody has to click anything. Success also depends on conditions the attacker does not fully control.
What an attacker gains
A successful attack can change data or behaviour and take it offline. In practice, this kind of flaw lets an attacker crash the process, read memory, or in the worst case run code.
Is it being exploited?
There is no public report of exploitation yet.
What to do
- Upgrade bacnet-stack to a fixed version for your release line (1.4.6, 1.5.2, 1.6.1).
- Until it is patched, keep it off the internet or behind a VPN, allowlist or authenticating proxy.
Description from NVD
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.
What this means for your architecture.
A CVE names a product. Whether it matters depends on where that product sits in your systems: what reaches it, which trust boundary it guards and what it can reach once compromised. Veriom maps your components, their relationships and your trust boundaries from your code, cloud and delivery evidence, so you can see where a component like this sits. The radar itself does not look at your systems.
Components it touches
- Native code: operating systems, browsers and firmware. The flaw sits wherever native code reads untrusted data.
- Network appliances and media or file parsers. The flaw sits wherever native code reads untrusted data.
Trust boundaries in play
- Internet-facing entry points. No account is needed. Any instance reachable from outside your perimeter, through a load balancer, gateway, VPN or exposed admin port, is in scope.
- Wherever native code reads untrusted data. An attacker who crosses it can crash the process, read memory, or in the worst case run code.
Questions to answer about your own systems
- Where does bacnet-stack run in your systems, and at which version?
- Which of those instances can be reached from the internet or partner networks?
- What can it reach once compromised: which data stores, secrets and services?
Read more
Sources
- CVE records and CVSS scores from the NVD CVE API. This product uses the NVD API but is not endorsed or certified by the NVD.
- Exploitation status from CISA’s Known Exploited Vulnerabilities catalog.
- Exploit likelihood from FIRST’s Exploit Prediction Scoring System (EPSS), refreshed daily.
- Explanations are written by Veriom from fixed templates over each record’s data, not by a person reviewing each CVE. Descriptions are quoted from the records as published.