CVE
BACnet Stack unauthenticated mesh join in BACnet/SC hub
Affects bacnet-stack BACnet/SC sc-hub builds made with BACDL=bsc and BACNET_PORT=linux and reachable on port 50050 over wss://. No fixed release is confirmed in the checked facts.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
- Exploited
- No known exploitation
- Fix
- Fixed in 1.4.6, 1.5.2, 1.6.1
- 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? →
- 0.33% · 26th 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
The BACnet Stack library's BACnet/SC hub accepts TLS connections from clients that present no certificate, so any network-reachable host can join the BACnet/SC mesh without credentials. An attacker can do this remotely, without logging in, and the advisory does not state which further impacts follow from that access.
Original description
BACnet Stack is a BACnet open source protocol stack C library for embedded systems. Prior to versions 1.4.6, 1.5.2, and 1.6.1, bws_srv_start() in ports/linux/websocket-srv.c builds the libwebsockets server context with a CA certificate loaded but never sets LWS_SERVER_OPTION_REQUIRE_VALID_OPENSSL_CLIENT_CERT, so the hub accepts TLS connections from clients presenting no certificate at all. Any network-reachable host can join the BACnet/SC mesh without credentials. This issue has been patched in versions 1.4.6, 1.5.2, 1.6.1, and 1.7.0.
Who should check
Teams running bacnet-stack 1.5.0 or earlier that build the BACnet/SC hub (sc-hub, bacschub or bacserv) on Linux, Windows or BSD ports
“bws_srv_start() in ports/linux/websocket-srv.c”
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
- Severity8.1/10CVSS 8.1
- 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: 1.4.6, 1.5.2, 1.6.1.
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-2026-102612 (BACnet Stack: BACnet/SC hub never requires a client cert, so any host joins the mesh unauthenticated), 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-2026-102612 (entry last updated 2026-11-13):
Affected:
- bacnet-stack bacnet-stack: fixed in 1.4.6; from 1.5.0, fixed in 1.5.2; from 1.6.0, fixed in 1.6.1
Fixed versions: 1.4.6, 1.5.2, 1.6.1.
Conditions (all must be true for the bug to be hit):
- Built with BACDL=bsc and BACNET_PORT=linux to make the BACnet/SC sc-hub (source: https://github.com/bacnet-stack/bacnet-stack/security/advisories/GHSA-92q2-p4vr-fvmp)
- The hub is network-reachable on port 50050 over wss:// (source: https://github.com/bacnet-stack/bacnet-stack/security/advisories/GHSA-92q2-p4vr-fvmp)
- The verify option is never set by the hub's server setup, regardless of configuration (source: https://github.com/bacnet-stack/bacnet-stack/security/advisories/GHSA-92q2-p4vr-fvmp)
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-2026-102612 is not listed as of cve.now's last read.
This KEV status is for CVE-2026-102612 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-92q2-p4vr-fvmp
- https://github.com/bacnet-stack/bacnet-stack/pull/1436
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-2026-102612
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-2026-102612"}.Timeline
- CVE published
- First seen by cve.now
Affected versions
- bacnet-stack bacnet-stack
fixed in 1.4.6; From 1.5.0 · fixed in 1.5.2; From 1.6.0 · fixed in 1.6.1
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-2026-102612
Is CVE-2026-102612 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?
The BACnet/SC hub never requires a client certificate, so any network-reachable host can join the mesh without credentials. A joining host can receive a Connect-Accept from the hub and be treated as a trusted node, which defeats the authenticity guarantee of BACnet/SC.Source: github.com
Which versions are affected by CVE-2026-102612?
bacnet-stack: before 1.4.6; from 1.5.0 before 1.5.2; from 1.6.0 before 1.6.1.Source: cve.now feed data
Am I affected, and how do I check?
The product data lists affected ranges before 1.4.6, from 1.5.0 up to 1.5.2, and from 1.6.0 up to 1.6.1. The setup matters: the hub must be built with BACDL=bsc and BACNET_PORT=linux to make sc-hub, and it must be reachable on port 50050 over wss://. Check the version you built and whether the hub listens on that port.Source: github.com
How do I fix CVE-2026-102612?
The checked facts do not name a confirmed fix for this advisory. The product data lists 1.4.6, 1.5.2 and 1.6.1 as the first fixed releases in their branches, but confirm that against the vendor advisory before relying on them. Until then, limit which hosts can reach port 50050 over wss://.Source: github.com