HackZoneLabs News
Newsletter

CVE-2026-62976

BACnet Stack: Consecutive AtomicWriteFile(record-access) appends can trigger a heap out-of-bounds read in the RAMFS file backend

  • High 8.7

Description

BACnet Stack is a BACnet open source protocol stack C library for embedded systems. Prior to version 1.5.1, the RAMFS-backed FILE object implementation stores appended records as NUL-terminated strings, but its record-counting logic later walks the buffer as if an additional terminating empty record were present. As a result, two consecutive AtomicWriteFile(record-access) append requests can cause record_count() to call bacnet_strnlen() on a pointer that is already one byte past the end of the heap allocation. This issue has been patched in versions 1.5.1 and 1.6.0.

Key facts

Published
13 Nov 2026
Last changed
13 Nov 2026
Assigned by
GitHub_M
EPSS
0.292% likely to be exploited in the next 30 days, higher than 22.001% of CVEs (scores for 15 Nov 2026)

Severity scores

Each score is shown as its source gave it. They are not averaged or merged.

  • 8.7CVSS 4.0, Highfrom the CNA (GitHub_M)CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Historical context and remediation

This reference retains the original CVE publication date. A recent record update does not mean a new attack occurred.

No separately sourced impact summary is available on this page yet. Consult the description, version data and dated exploitation evidence.

No explicit remediation statement is available on this page yet. Consult the original record and vendor references before choosing a fix.

Version statuses below come from the CNA. An “unaffected” version is not necessarily a currently supported release or proof of a patch date. EPSS is a dated risk estimate, not a count of historical attacks.

Read the original CVE record.

Affected products

VendorProductVersions
bacnet-stackbacnet-stack
  • < 1.5.1 (affected)

Timeline

  1. 13 Nov 2026 Published

Weakness

References