Integer Overflow, Improper Validation of Array Index, Uncontrolled Recursion and Memory Allocation with Excessive Size Value in the Go implementation of Apache PLC4X (PLC4Go) allow a malicious device, or an attacker able to inject network traffic, to crash or exhaust the memory of the client application, causing a denial of service.

The individual defects are: - Generated parsers pre-allocate arrays with the element count claimed on the wire (0.13.0 through 0.13.1). - Transport read helpers allocate buffers of the size claimed on the wire without an upper bound. - ADS and KNXnet/IP response handling indexes into received data without checking its length, causing a panic. - ADS and EIP frame-length handling accepts, or arithmetically wraps to, a length of zero, breaking message framing. - Recursive protocol types are parsed without a nesting-depth limit. The same defect in the Java implementation is covered by CVE-2026-102509 https://cveprocess.apache.org/cve5/CVE-2026-102509 .

Additionally, length and position arithmetic in generated serializers was performed in 16-bit integers. If an application forwards attacker-influenced payloads larger than 8 KB, the length field wraps, and the remainder of the payload may be interpreted by the receiving device (for example, an ADS PLC) as additional, independent protocol messages.

This issue affects Apache PLC4X: from 0.11.0 before 1.0.0. PLC4Go is consumed as the Go module github.com/apache/plc4x/plc4go; versions refer to the corresponding Apache PLC4X releases.

Users are recommended to upgrade to version 1.0.0, which fixes the issue.

Memory Allocation with Excessive Size Value, Allocation of Resources Without Limits, and Uncontrolled Recursion in the Java implementation of Apache PLC4X (PLC4J) allow a malicious or impersonated device to exhaust the memory or stack of the client application, causing a denial of service.

In the OPC UA driver these defects are reachable before authentication: the offending data is parsed while the secure channel and session are being established, before the server's identity has been bound to it. Configuring a trusted server therefore does not prevent exploitation by an attacker who can impersonate it.

The individual defects are: - Length-prefixed byte strings are allocated at the size claimed on the wire before the length is checked against the data actually received (0.10.0 through 0.13.1). - Array fields in generated protocol parsers pre-allocate a list with the element count claimed on the wire, allowing a single count field to trigger a multi-gigabyte allocation. This parser is shared by all PLC4J drivers; the OPC UA driver is the verified pre-authentication path (0.10.0 through 0.13.1). - The OPC UA driver accumulates message chunks without enforcing the negotiated maximum chunk count and message size (0.12.0 through 0.13.1). - The OPC UA driver pre-allocates collections using element counts received from the server (0.10.0 through 0.13.1). - Recursive protocol types are parsed without a nesting-depth limit. The same defect in the Go implementation is covered by CVE-2026-102510 https://cveprocess.apache.org/cve5/CVE-2026-102510 .

This issue affects Apache PLC4X: from 0.10.0 before 1.0.0.

Users are recommended to upgrade to version 1.0.0, which fixes the issue.