Severity by source
AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Lifecycle Timeline
6DescriptionCVE.org
An unauthenticated remote attacker may be able to control the format string of messages processed by the Audit Log of the CODESYS Control runtime system, potentially resulting in a denial‑of‑service (DoS) condition.
AnalysisAI
A format string vulnerability exists in the Audit Log component of CODESYS Control runtime system that allows unauthenticated remote attackers to inject malicious format specifiers into log messages. This affects numerous CODESYS Control products across multiple platforms including Windows, Linux, embedded systems (BeagleBone, Raspberry Pi, PFC100/200), and industrial controllers (Beckhoff CX, WAGO Touch Panels). Exploitation can lead to denial-of-service conditions by crashing the runtime system, with a CVSS score of 7.5 indicating high availability impact.
Technical ContextAI
This vulnerability stems from CWE-134 (Use of Externally-Controlled Format String), where user-controlled input is passed directly to format string functions without proper sanitization in the CODESYS Control runtime's Audit Log mechanism. CODESYS is a widely-deployed industrial automation development platform used in programmable logic controllers (PLCs) and embedded control systems. The affected products span the entire CODESYS Control family including runtime environments (RTE), development toolkits, platform-specific implementations for ARM and x86 Linux, Windows, and vendor-specific variants for industrial hardware from Beckhoff, WAGO, Phoenix Contact (PLCnext), and others. Format string vulnerabilities occur when attacker-supplied data containing format specifiers like %s, %n, or %x is processed by functions like printf, syslog, or similar logging functions, potentially causing crashes, memory corruption, or information disclosure depending on implementation.
RemediationAI
Consult the CERT@VDE security advisory VDE-2026-018 at https://certvde.com/de/advisories/VDE-2026-018 for vendor-provided patches and specific version updates that address this format string vulnerability. Until patches can be applied, implement network segmentation to restrict access to CODESYS runtime systems from untrusted networks, disable or restrict remote access to audit log functionality if operationally feasible, and deploy intrusion detection systems to monitor for format string attack patterns in network traffic targeting CODESYS services. Given the unauthenticated remote attack vector, prioritize applying vendor patches as soon as they become available and conduct thorough testing in non-production environments before deploying to operational industrial control systems. Organizations should also review audit log configurations to minimize exposure of log processing interfaces to external networks.
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Privilege escalation through unauthorized account deletion in CODESYS Control runtime products (versions below 3.5.22.20
Same weakness CWE-134 – Use of Externally-Controlled Format String
View allSame technique Information Disclosure
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External POC / Exploit Code
Leaving vuln.today
EUVD-2026-14784
GHSA-34rr-qp2j-p4q7