Remote Memory Exposure in BACnet Stack C Library for Embedded Systems
CVE-2026-62977

6.9MEDIUM

Key Information:

Vendor

Bacnet-stack

Status
Bacnet-stack
Vendor
CVE Published:
13 November 2026

What is CVE-2026-62977?

The BACnet Stack, an open-source protocol stack C library for embedded systems, contains a vulnerability in its FILE object implementation that allows remote clients to modify the size of a read-only stream-access file. This occurs when the WriteProperty(PROP_FILE_SIZE) operation does not verify whether the file is classified as Read_Only. When using RAMFS, enlarging the file calls realloc() without properly initializing the new memory region, potentially exposing stale or unintentional data to remote clients. Additionally, it is possible to truncate files that should remain unchanged. This flaw can expose sensitive information and has been addressed in versions 1.5.1 and 1.6.0.

Affected Version(s)

bacnet-stack < 1.5.1

References

https://github.com/bacnet-stack/bacnet-stack/security/adv...
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https://github.com/bacnet-stack/bacnet-stack/pull/1411
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CVSS V4

Score:
6.9
Severity:
MEDIUM
Confidentiality:
Low
Integrity:
Low
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.