CVE
BACnet Stack denial of service in address-binding encoding
Affects bacnet-stack 1.6.0-rc1 and earlier when a device caches I-Am messages from multiple distinct devices. CVSS rates it high (7.5). Fixed in 1.4.5, 1.5.1 and 1.6.0-rc2.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Exploited
- No known exploitation
- Fix
- Fixed in 1.4.5, 1.5.1, 1.6.0-rc2
- Who is exposed
- Not reported
Do first: Upgrade to a fixed version: 1.4.5, 1.5.1, 1.6.0-rc2.
- 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
- 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? →
- 25/100 · 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? →
- Unclear
- 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 has an out-of-bounds write flaw in how it encodes the device.address-binding property, which can be triggered remotely over the network without logging in. An attacker who reaches it can crash the affected software (a denial of service), since the impact is listed as availability only.
Original 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-rc2, a reachable out-of-bounds write exists when encoding the device.address-binding property. This issue has been patched in versions 1.4.5, 1.5.1, and 1.6.0-rc2.
cve.now Index
- Exploitation?/40Unknown. No CISA SSVC exploitation rating yet
- Exposure17/25No login or user action needed, reachable over the network without a login · Unknown: Advisories don't say whether default setups are affected
- 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
- Would score about 30 if advisories confirm default setups are exposed
What to do
Upgrade to a fixed version: 1.4.5, 1.5.1, 1.6.0-rc2.
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-2026-52787 (BACnet Stack: Global APDU transmit buffer out-of-bounds write in device.address-binding response encoding via address_list_encode()), 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-2026-52787 (entry last updated 2026-11-13):
Affected:
- bacnet-stack bacnet-stack: fixed in 1.4.5; fixed in 1.5.1; fixed in 1.6.0-rc2
Fixed versions: 1.4.5, 1.5.1, 1.6.0-rc2.
Conditions (all must be true for the bug to be hit):
- Affected versions are v1.6.0-rc1 and earlier (<= 1.6.0-rc1). (source: https://github.com/bacnet-stack/bacnet-stack/security/advisories/GHSA-4fgg-fghm-jm43)
- Device must have multiple I-Am messages from distinct devices cached in the address cache, then receive a ReadProperty for PROP_DEVICE_ADDRESS_BINDING on the local device object. (source: https://github.com/bacnet-stack/bacnet-stack/security/advisories/GHSA-4fgg-fghm-jm43)
Setup: unknown whether the bug needs a non-default feature or setting. Check the advisory.
Attacker needs: network access, no login, no user action.
CISA KEV: CVE-2026-52787 is not listed as of cve.now's last read.
This KEV status is for CVE-2026-52787 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-4fgg-fghm-jm43
- https://github.com/bacnet-stack/bacnet-stack/pull/1363
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-2026-52787
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-2026-52787"}.Timeline
- CVE published
- First seen by cve.now
Affected versions
- bacnet-stack bacnet-stack
fixed in 1.4.5; fixed in 1.5.1; fixed in 1.6.0-rc2
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-2026-52787
Is CVE-2026-52787 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 bug is an out-of-bounds write into the global APDU transmit buffer while the device address-binding response is encoded. Under ASAN the write reproduces as a process abort (denial of service), and non-ASAN builds still contain the memory corruption.Source: github.com
Which versions are affected by CVE-2026-52787?
bacnet-stack: before 1.4.5; before 1.5.1; before 1.6.0-rc2.Source: cve.now feed data
Am I affected, and how do I check?
Versions 1.6.0-rc1 and earlier are affected. The condition requires multiple valid BACnet/IP I-Am messages from distinct device IDs to be cached in the address cache, followed by a ReadProperty for PROP_DEVICE_ADDRESS_BINDING on the local device object. Check the bacnet-stack version in use against 1.6.0-rc1 to see where it falls relative to the affected range.Source: github.com
How do I fix CVE-2026-52787?
Upgrade to a fixed release: 1.4.5, 1.5.1, or 1.6.0-rc2, depending on which release line is in use.Source: github.com