Vulnerability · Published Apr 13, 2026 · Assigned by ABB
CVE-2025-3756Denial of Service Vulnerabilities in System 800xA, Symphony® Plus IEC 61850
Medium 6.5
In plain English
A medium-severity security flaw in AC800M (System 800xA) from ABB. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 8% of all known vulnerabilities).
Official description
A vulnerability exists in the command handling of the IEC 61850 communication stack included in the product revisions listed as affected in this CVE. An attacker with access to IEC 61850 networks could exploit the vulnera bility by using a specially crafted 61850 packet, forcing the communication interfaces of the PM 877, CI850 and CI868 modules into fault mode or causing unavailability of the S+ Operations 61850 connectivity, resulting in a denial-of-service situation. The System 800xA IEC61850 Connect is not affected. Note: This vulnerability does not impact on the overall availability and functionality of the S+ Operations node, only the 61850 communication function. This issue affects AC800M (System 800xA): from 6.0.0x through 6.0.0303.0, from 6.1.0x through 6.1.0031.0, from 6.1.1x through 6.1.1004.0, from 6.1.1x through 6.1.1202.0, from 6.2.0x through 6.2.0006.0; Symphony Plus SD Series: A_0, A_1, A_2.003, A_3.005, A_4.001, B_0.005; Symphony Plus MR (Melody Rack): from 3.10 through 3.52; S+ Operations: 2.1, 2.2, 2.3, 3.3.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| ABB | AC800M (System 800xA) | 6.0.0x – through 6.0.0303.06.1.0x – through 6.1.0031.06.1.1x – through 6.1.1004.06.1.1x – through 6.1.1202.06.2.0x – through 6.2.0006.0 |
| ABB | Symphony Plus SD Series | A_0A_1A_2.003A_3.005A_4.001B_0.005 |
| ABB | Symphony Plus MR (Melody Rack) | 3.10 – through 3.52 |
| ABB | S+ Operations | 2.12.22.33.3 |
Weakness: CWE-1284 · Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H