8.1

CVE-2026-26264

Exploit

BACnet Stack WriteProperty decoding length underflow leads to OOB read and crash

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.
Daten sind bereitgestellt durch National Vulnerability Database (NVD)
Bacnetstack ≫ Bacnet Stack Version >= 1.4.0 < 1.4.3
Bacnetstack ≫ Bacnet Stack Version1.4.3 Updaterc1
Bacnetstack ≫ Bacnet Stack Version1.5.0 Updaterc1
Bacnetstack ≫ Bacnet Stack Version1.5.0 Updaterc2
Bacnetstack ≫ Bacnet Stack Version1.5.0 Updaterc3
Zu dieser CVE wurde keine Warnung gefunden.
EPSS Metriken
Typ Quelle Score Percentile
EPSS FIRST.org 0.37% 0.284
CVSS Metriken
Quelle Base Score Exploit Score Impact Score Vector String
nvd@nist.gov 8.1 2.8 5.2
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
security-advisories@github.com 7.8 0 0
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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CWE-125 Out-of-bounds Read

The product reads data past the end, or before the beginning, of the intended buffer.

https://github.com/bacnet-stack/bacnet-stack/security/advisories/GHSA-phjh-v45p-gmjj
Vendor Advisory
Exploit
https://github.com/bacnet-stack/bacnet-stack/commit/4cc8067c86f26e2b08b2c8f4d27f8e07de4d4708
Patch