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NVD / CVE Program· CNA GitHub_M

CVE-2026-46676: BACnet Stack: Uninitialized Value Use in AtomicReadFile-ACK Record-Access Encoder Causes Response Corruption and Conditional Information Disclosure

MediumCVSS 5.3 · v3.1—No exploit No fix recorded

Noroxi assessment

Priority: Monitor (action score 21/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • No fixed version is recorded, but the references include a patch (commit or PR) link.

Low priority for now. See the fix and affected versions sections below.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org

BACnet Stack is a BACnet open source protocol stack C library for embedded systems. From versions 1.4.0 to before 1.4.4, and 1.5.0 to before 1.5.1, an uninitialized value use vulnerability in bacnet-stack's AtomicReadFile record-access ACK encoder allows unauthenticated remote attackers to corrupt the encoded OCTET STRING length and payload boundary in network responses by sending a crafted AtomicReadFile request that reaches a successful record-access path. This issue has been patched in versions 1.4.4 and 1.5.1.

Published
Nov 12, 2026
Updated
Nov 12, 2026
EPSS
—

Report tools

JSON

Action score

21

Monitor

Low priority for now.

CVSS
21 / 40 · 5.3 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · —

CNA vs NVD score

NVD
—
CNA · GitHub_M
5.3
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • No fixed version yet

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-46676

When you'll hear from us

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  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

  • bacnet-stack bacnet-stack

    • >= 1.4.0, < 1.4.4, >= 1.5.0, < 1.5.1affected

Same product

bacnet-stack: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-47711BACnet Stack: Stack buffer overflow in Loop internal ReadProperty path via Life_Safety_Zone.accepted-modes on the default BACnet/IP server
    34Monitor
  • CVE-2026-47710BACnet Stack: Loop reference to long Structured View description causes stack-buffer-overflow
    32Monitor
  • CVE-2026-47259BACnet Stack: Stack-based buffer overflow in Notification Class RemoveListElement recipient-list decoding
    32Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2026-45341Nov 12, 2026 · BACnet Stack: NULL pointer dereference in bacnet_device_object_reference_decode() when WriteProperty updates Structured View subordinate-list
    30Monitor
  • ← EarlierCVE-2026-46674Nov 12, 2026 · BACnet Stack: Out-of-Bounds Read in AtomicWriteFile Record Decoder via Unbounded returnedRecordCount
    30Monitor
  • Later →CVE-2026-46677Nov 12, 2026 · BACnet Stack: Client-Side Out-of-Bounds Read in AtomicReadFile-ACK Record-Access Handling via RecordCount / fileData[] Mismatch
    26Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

No fix version is recorded for this entry. Check the references for vendor advisories.

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

Not on record for this CVE: EPSS history · researcher credit · variant or chain candidate · public bounty program.

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
low · data can be read
Integrity
none
Availability
none
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
Low
Integrity impact
None
Availability impact
None

Weakness class (CWE)

CWE-457 · Use of Uninitialized Variable

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

References

Show all references (1 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records