CVE-2026-62975

MEDIUMCVSS 6.9/10

Last modified

CVE-2026-62975 is a medium-severity vulnerability rated 6.9/10 on the CVSS scale. BACnet Stack is a BACnet open source protocol stack C library for embedded systems. Prior to version 1.5.1, the RAMFS-backed FILE implementation accepts AtomicWriteFile(record-access) requests that replace existing records with caller-controlled content.

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 implementation accepts AtomicWriteFile(record-access) requests that replace existing records with caller-controlled content. If a client replaces a record with shorter data, the backend can shrink the heap allocation and then continue processing with a trailing-copy length derived from the old layout. During that replace path, the RAMFS backend computes the trailing-copy length from the old file layout, then shrinks the heap allocation, and finally uses the stale length in memmove(). As a result, the source range of that memmove() can extend beyond the end of the reallocated heap buffer, producing a heap out-of-bounds read. This issue has been patched in versions 1.5.1 and 1.6.0.

Metrics

Weakness Enumeration

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
bacnet-stackbacnet-stack< 1.5.1

References

Timeline

Published
Last Modified
Status
Awaiting Analysis

Frequently Asked Questions

What is CVE-2026-62975?
BACnet Stack is a BACnet open source protocol stack C library for embedded systems. Prior to version 1.5.1, the RAMFS-backed FILE implementation accepts AtomicWriteFile(record-access) requests that replace existing records with caller-controlled content. If a client replaces a record with shorter data, the backend can shrink the heap allocation and then continue processing with a trailing-copy length derived from the old layout. During that replace path, the RAMFS backend computes the trailing-copy length from the old file layout, then shrinks the heap allocation, and finally uses the stale length in memmove(). As a result, the source range of that memmove() can extend beyond the end of the reallocated heap buffer, producing a heap out-of-bounds read. This issue has been patched in versions 1.5.1 and 1.6.0.
How severe is CVE-2026-62975?
CVE-2026-62975 has a CVSS score of 6.9/10 (MEDIUM severity).
How do I fix CVE-2026-62975?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST