Summary
This advisory addresses multiple security vulnerabilities in PLCnext firmware versions prior to 2026.0.3. The vulnerabilities may allow unauthenticated attackers to cause denial of service, trigger unexpected system behavior, or execute unauthorized SQL queries. Successful exploitation could impact the availability, integrity, and confidentiality of affected PLCnext Control devices. All issues are resolved in PLCnext firmware version 2026.0.3.
Impact
The reported vulnerabilities allow an unauthenticated remote attacker to cause a denial-of-service condition, trigger unexpected behaviour through a buffer overflow, or execute unauthorized SQL queries against affected PLCnext devices. Successful exploitation could impact the availability, integrity, and confidentiality of the system.
Affected Product(s)
| Model no. | Product name | Affected versions |
|---|---|---|
| 1151412 | AXC F 1152 | <2026.0.3 |
| 1646469 | AXC F 1252 | <2026.0.3 |
| 1551772 | AXC F 2000 EA | <2026.0.3 |
| 2404267 | AXC F 2152 | <2026.0.3 |
| 1069208 | AXC F 3152 | <2026.0.3 |
| 1246285 | BPC 9102S | <2026.0.3 |
| 1839159 | BPC 9202S | <2026.0.3 |
| 1886438 | Catan C1 | <2026.0.3 |
| 1185416 | EPC 1502 | <2026.0.3 |
| 1185423 | EPC 1522 | <2026.0.3 |
| 1136419 | RFC 4072R | <2026.0.3 |
| 1051328 | RFC 4072S | <2026.0.3 |
| 1760157 | VL3 UPC 2440 EDGE | <2026.0.3 |
| 1737875 | VPLCNEXT CONTROL 1000 | <2026.0.3 |
| 1738453 | VPLCNEXT CONTROL 2000 | <2026.0.3 |
| 1738454 | VPLCNEXT CONTROL 3000 | <2026.0.3 |
| 1751491 | VPLCNEXT CONTROL 500 | <2026.0.3 |
Vulnerabilities
Expand / Collapse allThe device's PROFINET service is affected by a buffer overflow vulnerability that exists in the default configuration. An unauthenticated remote attacker could exploit this vulnerability to reboot the device or execute arbitrary code.
An unauthenticated denial-of-service vulnerability in the device's PLCnext Engineer communication interface allows an remote attacker to interrupt access via the client application. Successful exploitation prevents communication until the PLCnext service is manually restarted.
An authenticated attacker with low privileges can access an endpoint in the controller’s web interface that is vulnerable to SQL injection. The vulnerability affects a SQLite database used only for storing notification messages. Therefore, the impact is limited to the system’s notification functionality.
Remediation
Phoenix Contact recommends updating affected devices to PLCnext firmware version 2026.0.3 or later, which addresses all vulnerabilities described in this advisory.
Acknowledgments
Phoenix Contact GmbH & Co. KG thanks the following parties for their efforts:
- CERT@VDE for coordination. (see https://certvde.com )
- CyberDanube for Reporting.
Revision History
| Version | Date | Summary |
|---|---|---|
| 1.0.0 | 08/12/2026 12:00 | Initial |