An unauthenticated specially crafted packet sent by an attacker over the network will cause a denial-of-service (DoS) vulnerability. Vulnerability allows attacker to stop the PLC. After stopping (ERR LED flashing red), physical access to the PLC is required in order to restart the application. This issue affects: ABB AC500 V2 products with onboard Ethernet version 2.8.4 and prior versions.
An official patch is available. Apply the patch as soon as possible.
CVSS v4.0 Metrics
Exploitability
Attack VectorNetwork
ComplexityLow
RequirementsPresent
PrivilegesNone
User InteractionNone
Threat
Exploit MaturityPoC
Vulnerable System
ConfidentialityNone
IntegrityNone
AvailabilityHigh
Subsequent System
ConfidentialityNone
IntegrityNone
AvailabilityNone
Supplemental
SafetyNegligible
AutomatableYes
RecoveryAutomatic
Value DensityConcentrated
UrgencyMedium
Patch StatusOfficial Patch
Change Log
| Date | Source | Changes | Score |
|---|
| 2026-07-21 | PoC | E: U→P | 4.6 → 6.9 |
| 2026-07-21 | nvd | patch: Unavailable→Official Patch | 4.6 → 4.6 |
| 2026-07-21 | cve.org | initial, patch: Unavailable | 4.6 |
Affected Software
| Vendor | Product | Version |
|---|
| ABB | AC500 V2 products with onboard Ethernet | ≤ 2.8.4 versions |
| abb | ac500_cpu_firmware | < 2.8.5 |
Published: 2021-02-09
