CVE-2026-21878

HIGH EPSS 27.5%
Published Feb 13, 20264mo ago · Modified Jun 17, 20262w ago
7.5 CVSS 3.1
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 1.5.0.rc3, a vulnerability has been discovered in BACnet Stack's file writing functionality where there is no validation of user-provided file paths, allowing attackers to write files to arbitrary directories. This affects apps/readfile/main.c and ports/posix/bacfile-posix.c. This vulnerability is fixed in 1.5.0.rc3.

CVSS Details

Base Score
7.5
Exploitability
3.9
Impact
3.6
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality None
Integrity High
Availability None

Threat Intelligence

EPSS Exploit Probability
27.5% percentile
Exploit & Patch Status
Public Exploit Known
Patch Available

Weaknesses 1

CWE-22 Path Traversal Resource Mgmt

Affected Products 2

VendorProductVersionRange
bacnetstackbacnet_stack1.5.0any
bacnetstackbacnet_stack1.5.0any

References 2

  • github.com https://github.com/bacnet-stack/bacnet-stack/commit/c5dc00a77b4bc2550befa67a930b333e299c18f3
    Patch
  • github.com https://github.com/bacnet-stack/bacnet-stack/security/advisories/GHSA-p8rx-c26w-545j
    ExploitVendor Advisory

Remediation

  • github.com https://github.com/bacnet-stack/bacnet-stack/commit/c5dc00a77b4bc2550befa67a930b333e299c18f3
    Patch