VulnerabilityPublished 9 Mar 2026

CVE-2026-3631: DeltaWW COMMGR2 · Out-of-bounds Read

Affects DeltaWW COMMGR2Source CVE Database V5

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Not known to be exploited · CVSS 7.5 High.

Data as of 30 Oct 2026, 06:59 UTC

CVSS 3.1 base score

7.5High

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

EPSS: 0.9% chance of exploitation in 30 days – higher than 60% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

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

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: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 9 Mar 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 29 Oct 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

Affected software

Product	Affected	Fixed in
DeltaWWCOMMGR2	Affected <=2.11.0	Fixed in–

AI-suggested

Until an official patch is released, organizations should implement network segmentation to isolate COMMGR2 systems from untrusted networks and limit exposure. Deploy strict firewall rules to restrict access to COMMGR2 communication ports only to trusted management stations and devices. Monitor network traffic for unusual patterns or repeated connection attempts targeting COMMGR2 services to detect potential exploitation attempts early. Employ intrusion detection and prevention systems (IDS/IPS) configured to recognize anomalous behavior related to buffer over-read attacks. Conduct regular backups and develop incident response plans to quickly recover from potential DoS incidents. Coordinate with Delta Electronics for timely updates and apply patches immediately upon availability. Additionally, consider deploying application-layer gateways or proxies that can filter malformed packets potentially triggering the buffer over-read. Educate operational technology (OT) personnel about the vulnerability and the importance of maintaining strict access controls.

Description

Delta Electronics COMMGR2 has Buffer Over-read DoS vulnerability.

Impact

The primary impact of CVE-2026-3631 is denial of service, which can cause COMMGR2 to crash or become unresponsive, disrupting industrial and building automation operations. This disruption can lead to operational downtime, safety risks, and financial losses, especially in sectors reliant on continuous control system availability such as manufacturing plants, energy grids, and critical infrastructure facilities. Since the vulnerability can be exploited remotely without authentication or user interaction, attackers can launch attacks at scale, potentially causing widespread outages. Although confidentiality and integrity are not directly affected, the loss of availability in critical systems can indirectly impact safety and operational integrity. Organizations worldwide using Delta Electronics COMMGR2 in their industrial control environments face risks of operational interruptions and associated cascading effects on supply chains and service delivery.

CWE-125Out-of-bounds Read (opens in a new tab)
Base weaknessCWE Top 25 (2025): #8
The product reads data past the end, or before the beginning, of the intended buffer.
Implementation · Input Validation
Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
Architecture and Design · Language Selection
Use a language that provides appropriate memory abstractions.
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
V5.1.3 (opens in a new tab)
Attack patterns
Overread Buffers (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

filecenter.deltaww.com/news/download/doc/Delta-PCSA-2026-00005_COMMGR%202%20Multiple%20Vulnerabilities%20(CVE-2026-3630,%20CVE-2026-3631).pdf (opens in a new tab)

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 16 Mar 2026, 09:48 UTC

WeaknessesCWE-125

Technical details

References

Community reviews

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