{"id":"CVE-2026-102509","title":"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…","summary":"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…","severity":"high","cvss":8.7,"cvssVector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","cwe":["CWE-674","CWE-770","CWE-789"],"vendor":"Apache Software Foundation","product":"org.apache.plc4x:plc4j-spi","affected":["org.apache.plc4x:plc4j-spi >= 0.10.0 < 1.0.0","org.apache.plc4x:plc4j-driver-opcua >= 0.10.0 < 1.0.0"],"published":"2026-09-30","updated":"2026-09-30","sourceUpdated":"2026-09-30T09:17:14.100","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-102509","references":[{"url":"https://lists.apache.org/thread.html/qngc85qhnlj7kpk3z58z0xlxhz2tn6gp","label":"security@apache.org"}],"tags":["nvd","cve.org"],"cvssSource":"cna","ingestedAt":"2026-09-30T09:00:29.916Z","slug":"CVE-2026-102509","body":"## Overview\n\nMemory 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.\n\nIn 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 \nimpersonate it.\n\nThe individual defects are:\n- 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).\n- 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).\n- The OPC UA driver accumulates message chunks without enforcing the negotiated maximum chunk count and message size (0.12.0 through 0.13.1).\n- The OPC UA driver pre-allocates collections using element counts received from the server (0.10.0 through 0.13.1).\n- 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 .\n\nThis issue affects Apache PLC4X: from 0.10.0 before 1.0.0.\n\nUsers are recommended to upgrade to version 1.0.0, which fixes the issue.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":48,"depthScoreParts":{"impact":47.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}