CVSS 3.1
7.7 highCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:HCVE-2026-97692 BACnet Stack: pre-auth out-of-bounds read that escalates to an out-of-bounds write into global memory
High (7.7) in bacnet-stack bacnet-stack.
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.
Severity
- CWE
- CWE-787 Out-of-bounds Write
- Published
- Modified
- Assigned by
- GitHub_M (CNA)
- NVD analysis
- Awaiting analysis
- Record from
- the NVD, synced
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Affected
Versions
From the CNA's record in the CVE List.
| Product | Affected |
|---|---|
| bacnet-stack | < 1.4.6 |
| bacnet-stack | >= 1.5.0, < 1.5.2 |
| bacnet-stack | >= 1.6.0, < 1.6.1 |