VulnerabilityPublished 12 Nov 2026

CVE-2026-46676: bacnet-stack · Use of Uninitialized Variable

Affects bacnet-stackSource CVE Database V5

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Not known to be exploited · CVSS 5.3 Medium : upgrade to 1.5.1 or 1.4.4 when convenient.

Data as of 12 Nov 2026, 20:48 UTC

CVSS 3.1 base score

5.3Medium

How severe the flaw is on the 0–10 CVSS scale.

Thin evidence

One scorer or none

CVSS scores by source
CNA (GitHub_M)	CVSS 3.1	5.3

Patch: Available – fixed in 1.5.1, 1.4.4

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: Low
Integrity: None
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 12 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 12 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade bacnet-stack to 1.5.1 or 1.4.4.

Affected software

Product	Affected	Fixed in
bacnet-stackbacnet-stack	Affected >=1.5.0 <1.5.1	Fixed in 1.5.1
bacnet-stackbacnet-stack	Affected >=1.4.0 <1.4.4	Fixed in 1.4.4

AI-suggested

Upgrade bacnet-stack to version 1.4.4 or later, or 1.5.1 or later, where this vulnerability is fixed. No other mitigation is required as the issue is resolved in these versions.

Description

A use of uninitialized variable vulnerability exists in the bacnet-stack library versions 1.4.0 to before 1.4.4 and 1.5.0 to before 1.5.1. The flaw occurs in the AtomicReadFile record-access ACK encoder, allowing unauthenticated remote attackers to corrupt encoded OCTET STRING length and payload boundaries by sending crafted requests. This vulnerability has been fixed in versions 1.4.4 and 1.5.1.

CWE-457Use of Uninitialized Variable (opens in a new tab)
Variant weaknessLikelihood of exploit: High
The code uses a variable that has not been initialized, leading to unpredictable or unintended results.
Implementation · Attack Surface Reduction
Ensure that critical variables are initialized before first use.
Build and Compilation · Compilation or Build Hardening
Most compilers will complain about the use of uninitialized variables if warnings are turned on.
Implementation · Operation
When using a language that does not require explicit declaration of variables, run or compile the software in a mode that reports undeclared or unknown variables. This may indicate the presence of a typographic error in the variable's name.
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 12 Nov 2026, 20:48 UTC

WeaknessesCWE-457

Technical details

References

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