CVE-2026-49990

What it is

BACnet Stack is a BACnet open source protocol stack C library for embedded systems. From versions 1.4.2 to before 1.4.5, and 1.5.0 to before 1.5.1, a signed fileStartPosition taken from AtomicReadFile and AtomicWriteFile stream-access requests is not validated tightly enough before it reaches the RAM file backends. Practical impact includes: reliable denial of service via process crash, out-of-bounds read that may expose adjacent memory contents, or out-of-bounds write that may corrupt heap memory and destabilize the process. This issue has been patched in versions 1.4.5 and 1.5.1.

At a glance

Exploitability

Can be exploited over the network without logging in. High risk of service disruption.

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-06-02 18:30 UTC ReservedThe CVE id was reserved by its CNA
2. 2026-11-13 16:19 UTC PublishedDisclosed publicly on CVE.org and NVD
3. 2026-11-13 22:11 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: not scored yet.
• Severity: 8.6 HIGH (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2026-11-13 16:19 UTC

Last modified

2026-11-13 22:11 UTC

Weakness

CWE-125 · Out-of-bounds read

Record status

Awaiting Analysis

Attack profile CVSS 3.1 · 8.6

Attack vector

Network

Complexity

Low

Privileges needed

None

User interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

Low

Availability

High

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-49990.md and follow it. Check whether this project is affected by CVE-2026-49990. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

Copy as ticket · More options · Status badge