CVE-2026-26264

HIGH EPSS 28.6%
Published Feb 13, 20264mo ago · Modified Jun 17, 20262w ago
7.8 CVSS 4.0
High
Find Similar
Published Feb 13, 2026 4mo ago
Last Modified Jun 17, 2026 2w ago

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 Details

Base Score
7.8
Exploitability
—
Impact
—
Vector string
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
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope X

Threat Intelligence

EPSS Exploit Probability
28.6% percentile
Exploit & Patch Status
Public Exploit Known
Patch Available

Weaknesses 1

CWE-125 Out-of-bounds Read Memory Safety

Affected Products 5

VendorProductVersionRange
bacnetstackbacnet_stack*≥1.4.0  –  <1.4.3
bacnetstackbacnet_stack1.4.3any
bacnetstackbacnet_stack1.5.0any
bacnetstackbacnet_stack1.5.0any
bacnetstackbacnet_stack1.5.0any

References 2

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

Remediation

  • github.com https://github.com/bacnet-stack/bacnet-stack/commit/4cc8067c86f26e2b08b2c8f4d27f8e07de4d4708
    Patch