CVE-2025-3756

Communication outage via malformed IEC 61850 message

Published Apr 13, 2026 · Updated Apr 13, 2026

Improper input validation in affected ABB controllers and S+ Operations allows adjacent unauthenticated attackers to interrupt IEC 61850 communications. The stack mishandles a specially crafted IEC 61850 message during command processing, placing PM 877, CI850, and CI868 interfaces in fault mode or crashing the S+ Operations communication driver. Access to the IEC 61850 network is required; hardware recovery requires manual reset, while repeated messages disrupt only S+ Operations IEC 61850 connectivity.

CVSS severity7.1
High
EPSS probability0.18%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper input validation in affected ABB controllers and S+ Operations allows adjacent unauthenticated attackers to interrupt IEC 61850 communications. The stack mishandles a specially crafted IEC 61850 message during command processing, placing PM 877, CI850, and CI868 interfaces in fault mode or crashing the S+ Operations communication driver. Access to the IEC 61850 network is required; hardware recovery requires manual reset, while repeated messages disrupt only S+ Operations IEC 61850 connectivity.

The record

CVE
CVE-2025-3756
Published
Apr 13, 2026
Updated
Apr 13, 2026
Vendor
GENEREX SYSTEMS Computervertriebsgesellschaft mbH
Product
ABB Ability Symphony Plus S+ Operations
Classifications
CWE-1284, T0814
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 13, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 13, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=2.1
  2. Affected versionversion=2.2
  3. Affected versionversion=2.3
  4. Affected versionversion=3.3

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

GENEREX SYSTEMS Computervertriebsgesellschaft mbH · ABB Ability Symphony Plus S+ Operationsversion=2.1; version=2.2; version=2.3; version=3.3
GENEREX SYSTEMS Computervertriebsgesellschaft mbH · ABB Symphony Plus MR Series Control and I/Oversion=3.10 <=3.52
GENEREX SYSTEMS Computervertriebsgesellschaft mbH · ABB AC 800M Controllerversion=6.0.0x <=6.0.0303.0; version=6.1.0x <=6.1.0031.0; version=6.1.1x <=6.1.1004.0; version=6.1.1x <=6.1.1202.0; version=6.2.0x <=6.2.0006.0
GENEREX SYSTEMS Computervertriebsgesellschaft mbH · ABB Ability Symphony Plus SD Series Control and I/Oversion=A_0; version=A_1; version=A_2.003; version=A_3.005; version=A_4.001; version=B_0.005

Published CVSS scores

6.5ABBCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
7.1ABBCVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-1284Improper Validation of Specified Quantity in Input
T0814Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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