CVE-2026-40279
- Source
- https://cve.org/CVERecord?id=CVE-2026-40279
- Import Source
- https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-40279.json
- JSON Data
- https://api.osv.dev/v1/vulns/CVE-2026-40279
- Aliases
-
- GHSA-326g-j95f-gmxv
- Published
- 2026-04-21T16:29:16.125Z
- Modified
- 2026-07-08T08:05:09.609187429Z
- Severity
-
- 3.7 (Low) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L CVSS Calculator
- Summary
- BACnet Stack: Undefined-behavior signed left shift in `decode_signed32()`
- Details
-
BACnet Stack is a BACnet open source protocol stack C library for embedded systems. Prior to 1.4.3, decodesigned32() in src/bacnet/bacint.c reconstructs a 32-bit signed integer from four APDU bytes using signed left shifts. When any of the four bytes has bit 7 set (value ≥ 0x80), the left-shift operation overflows a signed int32t, which is undefined behavior per the C standard. This is flagged thousands of times per minute by UndefinedBehaviorSanitizer on any BACnet input containing signed-integer property values with high-bit-set bytes. This vulnerability is fixed in 1.4.3.
- Database specific
{ "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/40xxx/CVE-2026-40279.json", "cna_assigner": "GitHub_M", "cwe_ids": [ "CWE-758" ] }- References
Affected packages
Git / github.com/bacnet-stack/bacnet-stack
Affected ranges
- Type
- GIT
- Repo
- https://github.com/bacnet-stack/bacnet-stack
- Events
-
Introduced0 Unknown introduced commit / All previous commits are affectedFixed
- Database specific
{ "source": [ "AFFECTED_FIELD", "CPE_RANGE" ], "cpe": "cpe:2.3:a:bacnetstack:bacnet_stack:*:*:*:*:*:*:*:*", "extracted_events": [ { "introduced": "0" }, { "fixed": "1.4.3" } ] }