CVE-2026-62975

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.

Severity scores

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

• 6.9CVSS 4.0, Mediumfrom the CNA (GitHub_M)CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/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

Timeline

1. 13 Nov 2026 Published

Weakness

• CWE-125

References

• https://github.com/bacnet-stack/bacnet-stack/security/advisories/GHSA-cf8g-hp9m-9fvvx_refsource_CONFIRM
• https://github.com/bacnet-stack/bacnet-stack/pull/1408x_refsource_MISC