CVE
BACnet Stack buffer overflow in WebSocket URL parser
Affects bacnet-stack builds that use the BACnet/SC datalink and process Address Resolution ACK messages. Fixed in 1.4.5, 1.5.1, and 1.6.0.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N
- Exploited
- No known exploitation
- Fix
- Fixed in 1.4.5, 1.5.1, 1.6.0
- Who is exposed
- Not reported
Do first: Upgrade to a fixed version: 1.4.5, 1.5.1, 1.6.0.
- 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? →
- 0.27% · 20th 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? →
- 26/100 · 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
BACnet Stack has buffer overflow bugs in its parsing of WebSocket URIs in BACnet/SC Address Resolution ACK messages. An attacker can send a crafted message over the network without logging in or taking any user action, causing writes past the end of a memory array that can corrupt data and disrupt the software.
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, the bsc_node_parse_urls() function in src/bacnet/datalink/bsc/bsc-node.c contains three distinct bugs when parsing space-separated WebSocket URIs from a BACnet/SC Address Resolution ACK message. Two bugs cause out-of-bounds writes past the utf8_urls[10][129] array in the static BSC_ADDRESS_RESOLUTION structure. This issue has been patched in versions 1.4.5, 1.5.1, and 1.6.0.
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
- Severity8.8/10CVSS 8.8
- No patch0/5No signal
What would change the score
- Would score about 71 if added to CISA KEV
- Would score about 66 if CISA's SSVC rates exploitation active
- Would score about 31 if advisories confirm default setups are exposed
What to do
Upgrade to a fixed version: 1.4.5, 1.5.1, 1.6.0.
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-2026-52788 (BACnet Stack: Buffer overflows in bsc_node_parse_urls() (BACnet/SC Address Resolution ACK URL parser)), 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-2026-52788 (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
Fixed versions: 1.4.5, 1.5.1, 1.6.0.
Conditions (all must be true for the bug to be hit):
- Uses the BACnet/SC datalink, processing Address Resolution ACK messages in bsc_node_parse_urls(). (source: https://github.com/bacnet-stack/bacnet-stack/security/advisories/GHSA-rf83-3rr5-v4mj)
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-2026-52788 is not listed as of cve.now's last read.
This KEV status is for CVE-2026-52788 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-rf83-3rr5-v4mj
- https://github.com/bacnet-stack/bacnet-stack/pull/1365
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-2026-52788
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-2026-52788"}.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
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-2026-52788
Is CVE-2026-52788 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 bsc_node_parse_urls() function in bsc-node.c has three separate bugs when it parses space-separated WebSocket URIs from a BACnet/SC Address Resolution ACK message. These bugs overflow buffers and corrupt adjacent static data, which can cause denial of service or potentially code execution.Source: github.com
Which versions are affected by CVE-2026-52788?
bacnet-stack: before 1.4.5; before 1.5.1; before 1.6.0.Source: cve.now feed data
Am I affected, and how do I check?
The issue is in bacnet-stack builds that use the BACnet/SC datalink and process Address Resolution ACK messages through bsc_node_parse_urls(). Fixed releases are 1.4.5, 1.5.1, and 1.6.0, so check the installed version and whether the BACnet/SC datalink is in use.Source: github.com
How do I fix CVE-2026-52788?
Upgrade to a fixed release: 1.4.5, 1.5.1, or 1.6.0.Source: github.com