MMS service crash via unchecked BER length
Published Jul 30, 2026 · Updated Jul 30, 2026
Out-of-bounds read in libIEC61850 before 1.6.2 allows remote attackers on an adjacent network to crash the MMS service with malformed BER data. The MMS BER decoder accepts an attacker-controlled length for fixed-width boolean or integer fields and reads beyond the associated heap buffer. Unauthenticated MMS reachability is sufficient; the reported consequence is service-process termination without data disclosure or modification.
Summary
What happened
Out-of-bounds read in libIEC61850 before 1.6.2 allows remote attackers on an adjacent network to crash the MMS service with malformed BER data. The MMS BER decoder accepts an attacker-controlled length for fixed-width boolean or integer fields and reads beyond the associated heap buffer. Unauthenticated MMS reachability is sufficient; the reported consequence is service-process termination without data disclosure or modification.
The record
- CVE
- CVE-2026-65421
- Published
- Jul 30, 2026
- Updated
- Jul 30, 2026
- Vendor
- MZ Automation GmbH
- Product
- libIEC61850
- Classifications
- CWE-125, T1499.004
- Attack vector
- adjacent
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 30, 2026CVE publishedPublication date reported by the CVE source.
- Jul 30, 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?
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- Affected versionversion=0 <1.6.2
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
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Public exploit references
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Technologies
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