CyberSecBulletin
CVE-2026-62974NVD status: Awaiting Analysis

bacnet-stack: Loop with Unreachable Exit Condition

Published Updated By the CyberSecBulletin desk

CVE-2026-62974 is a high-severity loop with unreachable exit condition vulnerability in bacnet-stack, with a CVSS 4.0 base score of 8.7 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 0.27% 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.
Attack requirements
NoneThe attack does not depend on a particular deployment or configuration.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Confidentiality (vulnerable system)
NoneNo loss of confidentiality on the vulnerable system.
Integrity (vulnerable system)
NoneNo loss of integrity on the vulnerable system.
Availability (vulnerable system)
HighSerious loss of availability on the vulnerable system.
Confidentiality (other systems)
NoneNo loss of confidentiality on systems beyond the vulnerable one.
Integrity (other systems)
NoneNo loss of integrity on systems beyond the vulnerable one.
Availability (other systems)
NoneNo loss of availability on systems beyond the vulnerable one.

Vector: 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. 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 malformed but non-empty BACnet WriteProperty request can drive the official server demo into a non-terminating request-processing loop with repeated heap-backed side effects. This results in a remote unauthenticated denial of service via uncontrolled resource consumption and a non-terminating request path. 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: Loop with Unreachable Exit Condition

The product contains an iteration or loop with an exit condition that cannot be reached, i.e., an infinite loop.

More Loop with Unreachable Exit Condition vulnerabilities (CWE-835)

Timeline

  1. CVE record published.

References

Other vulnerabilities in bacnet-stack

All bacnet-stack vulnerabilities

Recent Loop with Unreachable Exit Condition vulnerabilities

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