{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "cpe": "cpe:2.3:a:bacnetstack:bacnet_stack:*:*:*:*:*:*:*:*",
            "extracted_events": [
              {
                "introduced": "1.4.0"
              },
              {
                "fixed": "1.4.3"
              }
            ],
            "source": [
              "AFFECTED_FIELD",
              "CPE_RANGE"
            ]
          },
          "events": [
            {
              "introduced": "f332225b196aa66503faae64f92bef113fe89ab2"
            },
            {
              "fixed": "6d2d251ca4f4d932664add702b236279863d630a"
            }
          ],
          "repo": "https://github.com/bacnet-stack/bacnet-stack",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-5w2v-mwqj-pr2c"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-125"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/41xxx/CVE-2026-41503.json"
  },
  "details": "BACnet Stack is a BACnet open source protocol stack C library for embedded systems. Prior to 1.4.3, an out-of-bounds read vulnerability in bacnet-stack's ReadPropertyMultiple service property decoder allows unauthenticated remote attackers to read past allocated buffer boundaries by sending an RPM request with a truncated property list. The vulnerability stems from rpm_decode_object_property() calling the deprecated decode_tag_number_and_value() function at src/bacnet/rpm.c:344, which accepts no buffer length parameter and reads blindly from whatever pointer it receives. A crafted BACnet/IP packet with a 1-byte property payload containing an extended tag marker (0xF9) causes the decoder to read 1 byte past the end of the buffer, leading to crashes on embedded BACnet devices. The vulnerability exists in src/bacnet/rpm.c and affects any deployment that enables the ReadPropertyMultiple confirmed service handler (enabled by default in the reference server). This vulnerability is fixed in 1.4.3.",
  "id": "CVE-2026-41503",
  "modified": "2026-07-15T01:48:53.134667738Z",
  "published": "2026-04-24T19:41:44.071Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/41xxx/CVE-2026-41503.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/bacnet-stack/bacnet-stack/security/advisories/GHSA-5w2v-mwqj-pr2c"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-41503"
    }
  ],
  "schema_version": "1.8.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "BACnet Stack: Out-of-Bounds Read in ReadPropertyMultiple Property Decoder via Deprecated Tag Parser"
}