CVE-2026-21878CWE-22

BACnet Stack Improperly Limits Pathnames to a Restricted Directory

High · published February 13, 2026

CVSS v3.1
7.5
EPSS
0%
Percentile
34.5
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
7.5 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
CVSS v4.0
Not supplied
EPSS
0.00413 · 34.5th percentile
Weakness
CWE-22 · Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Published
2026-02-13T18:10Z
EPSS history
Timeline
  • 13 FEB 18:10Z
    BACnet Stack Improperly Limits Pathnames to a Restricted Directory
    cvelistv5