Runtime crash via externally controlled format string
Published Mar 24, 2026 · Updated Mar 24, 2026
Externally controlled format strings in affected CODESYS Control runtimes allow remote attackers to crash the runtime over a network. The CmpAuditLog component processes attacker-controlled log-message content as a format string rather than as data. Exploitation requires the Audit Log logger to be enabled and interrupts PLC operation by terminating the runtime, without reported confidentiality or integrity impact.
Summary
What happened
Externally controlled format strings in affected CODESYS Control runtimes allow remote attackers to crash the runtime over a network. The CmpAuditLog component processes attacker-controlled log-message content as a format string rather than as data. Exploitation requires the Audit Log logger to be enabled and interrupts PLC operation by terminating the runtime, without reported confidentiality or integrity impact.
The record
- CVE
- CVE-2026-3509
- Published
- Mar 24, 2026
- Updated
- Mar 24, 2026
- Vendor
- CODESYS GmbH
- Product
- CODESYS Control for BeagleBone SL
- Classifications
- CWE-134, CAPEC-67, CAPEC-135, T0814
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Mar 24, 2026CVE publishedPublication date reported by the CVE source.
- Mar 24, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=4.1.0.0 <4.21.0.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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