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CVE-2026-62973NVD status: Awaiting Analysis

bacnet-stack: Out-of-bounds Read

CVE-2026-62973 is a high-severity out-of-bounds read vulnerability in bacnet-stack, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected bacnet-stack versions: < 1.4.5; < 1.5.1; < 1.6.0. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.43% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of bacnet-stack you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on github.com for workarounds and exact fixed builds.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
Bacnet-stackbacnet-stack< 1.4.5; < 1.5.1; < 1.6.0Not stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
NoneNo data is disclosed.
Integrity
NoneNothing can be modified.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by CNA (github.com).

Official description

BACnet Stack is a BACnet open source protocol stack C library for embedded systems. Prior to versions 1.4.5, 1.5.1, and 1.6.0, a remote out-of-bounds read exists in the official BACnet client application apps/readpropm in bacnet-stack commit e2bdbf6. When readpropm sends a legitimate ReadPropertyMultiple request to a malicious BACnet/IP peer, the peer can reply with a malformed but structurally valid ReadPropertyMultiple-ACK that drives the client into a global-buffer-overflow read on the global receive buffer Rx_Buf. This issue has been patched in versions 1.4.5, 1.5.1, and 1.6.0.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Out-of-bounds Read

The product reads data past the end, or before the beginning, of the intended buffer.

How developers prevent this class of flaw

  • Use a language that provides appropriate memory abstractions.

More Out-of-bounds Read vulnerabilities (CWE-125)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: poc, automatable: yes, technical impact: partial).

References

Other vulnerabilities in bacnet-stack

All bacnet-stack vulnerabilities

Recent Out-of-bounds Read vulnerabilities

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