CVE
BACnet Stack stack overflow via self-referencing channel object
Affects bacnet-stack up to and including 1.5.0 in the default BACnet/IP server with the Channel object (channel-1). Fixed in 1.4.4 and 1.5.1.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
- Exploited
- No known exploitation
- Fix
- Fixed in 1.4.4, 1.5.1
- Who is exposed
- Default setups
Do first: Check every install: default setups are affected.
- Last modified
- Whether it needs action now or is a reference record, by fixed rules, with why. Last checked is when cve.now last re-read it.What do these mean? →
- Reference
- Last checked
- FIRST's estimate of the chance attackers exploit it in the next 30 days, updated daily.What do these mean? →
- 0.38% · 32nd percentile
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 30/100 · provisional
- How many real-world setups can hit the bug, from the vendor's advisory and CISA data. It does not know your setup.What do these mean? →
- Default setups
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
BACnet Stack, a BACnet protocol library for embedded systems, is affected. A remote attacker who can reach the default server over the network, without logging in, can abuse the Channel object to trigger uncontrolled recursion and a stack overflow.
Read the original description
BACnet Stack is a BACnet open source protocol stack C library for embedded systems. Prior to versions 1.4.4 and 1.5.1, a remote attacker can trigger an uncontrolled recursion and stack overflow in the default server application of bacnet-stack by abusing the Channel object. This issue has been patched in versions 1.4.4 and 1.5.1.
cve.now Index
- Exploitation?/40Unknown. No CISA SSVC exploitation rating yet
- Exposure22/25Default setups, reachable over the network without a login
- Reach?/20Unknown. No tracked technology or package matched
- Severity7.5/10CVSS 7.5
- No patch0/5No signal
What would change the score
- Would score about 70 if added to CISA KEV
- Would score about 65 if CISA's SSVC rates exploitation active
What to do
Check every install: default setups are affected.
Upgrade to a fixed version: 1.4.4, 1.5.1.
Check your systems with an agent
Paste this into a coding or ops agent. It checks your systems read-only and reports a table per asset.
Check whether my systems are affected by CVE-2026-47217 (BACnet Stack: Channel member self-reference causes uncontrolled recursion and stack overflow in default BACnet/IP server), using the cve.now data below.
Rules: work read-only. Do not run exploit code, proof-of-concept scripts or scanners that send attack payloads, and do not change any configuration, package, image or deployment. Report findings only.
What cve.now has for CVE-2026-47217 (entry last updated 2026-11-12):
Affected:
- bacnet-stack bacnet-stack: fixed in 1.4.4; fixed in 1.5.1
Fixed versions: 1.4.4, 1.5.1.
Conditions (all must be true for the bug to be hit):
- Affected versions are bacnet-stack up to and including 1.5.0 (patched in 1.4.4 and 1.5.1). (source: https://github.com/bacnet-stack/bacnet-stack/security/advisories/GHSA-wjw5-q9g6-2764)
- The default BACnet/IP server application with the Channel object (channel-1 in the example object set) is affected. (source: https://github.com/bacnet-stack/bacnet-stack/security/advisories/GHSA-wjw5-q9g6-2764)
Setup: the bug is reachable in a default setup; no special feature or setting is needed.
Attacker needs: network access, no login, no user action.
CISA KEV: CVE-2026-47217 is not listed as of cve.now's last read.
This KEV status is for CVE-2026-47217 only. If you also check another CVE, look up its own KEV status; never assume it from this one.
How to check:
- Installed software: check what is actually running, not what a repo declares. Read the version from each host, container image and Kubernetes node (the binary's version output, the OS package database, image layers), and check whether the conditions above hold there. Distribution packages may carry a backported fix under an older version number; confirm against the distribution's own advisory.
Verify against the linked advisories before concluding, and cite the date you read each one:
- https://github.com/bacnet-stack/bacnet-stack/security/advisories/GHSA-wjw5-q9g6-2764
- https://github.com/bacnet-stack/bacnet-stack/pull/1345
Do not conclude an asset is unaffected unless you checked it and the evidence covers both its version and the conditions above. If you could not check something, mark it unknown and say what is missing.
Report a table with one row per asset and these columns: Asset | Version or build | Status (affected, fixed, not applicable, unknown) | Compensating controls | Exposure (internet-facing, internal, none) | Evidence | Next action.
Entry: https://cve.now/CVE-2026-47217
For follow-up questions, use the cve.now MCP server at https://mcp.cve.now/mcp (no authentication), for example execute with name cve.get and arguments {"id": "CVE-2026-47217"}.Timeline
- CVE published
- First seen by cve.now
Affected versions
- bacnet-stack bacnet-stack
fixed in 1.4.4; fixed in 1.5.1
Evidence 4
Vendor advisory · 1
Establishes: Affected and fixed versions.
- Advisory
CVE record · 2
Establishes: The identifier and description.
- Record
- Record
Other links · 1
- Repository
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-47217
Is CVE-2026-47217 being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data
What does this mean?
A Channel object that references itself as a member causes unbounded recursion when two crafted WriteProperty requests are handled. The stack overflows and crashes the BACnet/IP server process, a remote denial of service.Source: github.com
Which versions are affected by CVE-2026-47217?
bacnet-stack: before 1.4.4; before 1.5.1.Source: cve.now feed data
Am I affected, and how do I check?
Versions of bacnet-stack up to and including 1.5.0 are affected. The issue applies to the default BACnet/IP server application that includes the Channel object, channel-1 in the example object set. To check, compare the bacnet-stack version in use against 1.5.0 and look for a channel-1 object in the object set.Source: github.com
How do I fix CVE-2026-47217?
Upgrade to bacnet-stack 1.4.4 or 1.5.1, which are the fixed versions.Source: github.com