Hang or crash via unchecked ACSE decoding errors
Published Oct 16, 2026 · Updated Oct 16, 2026
DoS in MZ Automation GmbH libIEC61850 before 1.6.2 allows remote attackers to hang ACSE parsing via malformed association responses. In src/mms/iso_acse/acse.c, parseUserInformation skips zero-length input before checking the decoder's negative position, causing a one-byte out-of-bounds read and repeated parsing. The path runs before authentication during MMS association; normal allocation produces an infinite CPU loop, while an inaccessible preceding byte causes a process abort.
Summary
What happened
DoS in MZ Automation GmbH libIEC61850 before 1.6.2 allows remote attackers to hang ACSE parsing via malformed association responses. In src/mms/iso_acse/acse.c, parseUserInformation skips zero-length input before checking the decoder's negative position, causing a one-byte out-of-bounds read and repeated parsing. The path runs before authentication during MMS association; normal allocation produces an infinite CPU loop, while an inaccessible preceding byte causes a process abort.
The record
- CVE
- CVE-2026-68906
- Published
- Oct 16, 2026
- Updated
- Oct 16, 2026
- Vendor
- MZ Automation GmbH
- Product
- libIEC61850
- Classifications
- CWE-835, CWE-125, T1499
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Oct 16, 2026CVE publishedPublication date reported by the CVE source.
- Oct 16, 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=< 1.6.2
What conditions does exploitation require?
What is affected?
Published CVSS scores
No CVSS assessment is available in this record.
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Activity data is delayed. The latest report is Sep 28, 2026.
Weakness, pattern, technique
Public exploit references
- Upstream ACSE parser proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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