{"id":"CVE-2026-100403","summary":"BACnet Stack: BACnet/SC hub grows its WebSocket reassembly buffer without limit, so a peer can exhaust its memory","details":"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 hub's Linux WebSocket server reassembles fragmented WebSocket messages into a per-connection fragment_buffer. It grows that buffer with realloc() on every non-final frame, with no upper bound. A peer that streams binary continuation fragments and never sets FIN keeps the hub reallocating until the box runs out of memory or the process is OOM-killed. The buffer starts at the maximum legal BVLC-SC NPDU size, but nothing after that ties its growth back to that limit. This issue has been patched in versions 1.4.6, 1.5.2, 1.6.1, and 1.7.0.","aliases":["GHSA-4vgv-v5ph-rmxr"],"modified":"2026-11-14T10:45:21.908879256Z","published":"2026-11-13T18:41:06.709Z","database_specific":{"cwe_ids":["CWE-400"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/100xxx/CVE-2026-100403.json","cna_assigner":"GitHub_M"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/100xxx/CVE-2026-100403.json"},{"type":"FIX","url":"https://github.com/bacnet-stack/bacnet-stack/pull/1433"},{"type":"ADVISORY","url":"https://github.com/bacnet-stack/bacnet-stack/security/advisories/GHSA-4vgv-v5ph-rmxr"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-100403"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/bacnet-stack/bacnet-stack","events":[{"introduced":"0"},{"fixed":"92e503566c990269f85ee15370d88415ad7ff6fb"},{"introduced":"61a7a53bea5b5bc4724646abbce601fd26c364b6"},{"fixed":"d2468d56de3d156659a9051c95119e3a6e11c421"},{"introduced":"9bc3cfa07aab98852de432fa24079f4b4b6b7eed"},{"fixed":"7a53f0a72a92de1621d30fc63703a29afe12bfaf"}],"database_specific":{"extracted_events":[{"source":"AFFECTED_FIELD","strategy":"StringRangeExpression","range":[{"introduced":"0"},{"fixed":"1.4.6"}]},{"range":[{"introduced":"1.5.0"},{"fixed":"1.5.2"}],"source":"AFFECTED_FIELD","strategy":"StringRangeExpression"},{"strategy":"StringRangeExpression","range":[{"introduced":"1.6.0"},{"fixed":"1.6.1"}],"source":"AFFECTED_FIELD"}]}}],"versions":["bacnet-stack-1.4.5","bacnet-stack-1.5.1","bacnet-stack-1.6.0","bacnet-stack-1.4.4","bacnet-stack-1.5.0","bacnet-stack-1.4.3","bacnet-stack-1.4.0","bacnet-stack-1.3.8","bacnet-stack-1.3.7","bacnet-stack-1.3.6","bacnet-stack-1.3.5","bacnet-stack-1.3.4","bacnet-stack-1.3.3","bacnet-stack-1.3.2","bacnet-stack-1.3.1","bacnet-stack-1.3.0","bacnet-stack-1.2.0","bacnet-stack-1.1.1","bacnet-stack-1.0.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-100403.json"}}],"schema_version":"1.9.2","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}