{"cve":"CVE-2026-26264","nvd":{"published":"2026-02-13T19:17:31.143","modified":"2026-06-17T10:26:00.427","status":"Analyzed","description":"BACnet Stack is a BACnet open source protocol stack C library for embedded systems. Prior to 1.5.0rc4 and 1.4.3rc2, a malformed WriteProperty request can trigger a length underflow in the BACnet stack, leading to an out‑of‑bounds read and a crash (DoS). The issue is in wp.c within wp_decode_service_request. When decoding the optional priority context tag, the code passes apdu_len - apdu_size to bacnet_unsigned_context_decode without validating that apdu_size <= apdu_len. If a truncated APDU reaches this path, apdu_len - apdu_size underflows, resulting in a large size being used for decoding and an out‑of‑bounds read. This vulnerability is fixed in 1.5.0rc4 and 1.4.3rc2.","cvss_v4":{"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:H/SC:N/SI:N/SA:N/E:P","score":7.8},"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","score":8.1},"cwes":["CWE-125"],"references":["https://github.com/bacnet-stack/bacnet-stack/commit/4cc8067c86f26e2b08b2c8f4d27f8e07de4d4708","https://github.com/bacnet-stack/bacnet-stack/security/advisories/GHSA-phjh-v45p-gmjj"],"products":["bacnetstack:bacnet_stack"],"source":"nvd","synced_at":"2026-10-19T22:23:35.260773158+00:00"},"epss":{"cve":"CVE-2026-26264","score":0.00427,"percentile":0.36977,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}