CVE-2026-19259 — MZ Automation libiec61850 MMS Protocol Workflow iec61850_common.c MmsMapping_varAccessSpecToObjectReference heap-based overflow
A vulnerability has been found in MZ Automation libiec61850 up to 1.6.1. The affected element is the function MmsMapping_varAccessSpecToObjectReference of the file src/iec61850/common/iec61850_common.c of the component MMS Protocol Workflow. Such manipulation of the argument GetNamedVariableListAttributesResponse.itemId leads to heap-based buffer overflow. The attack must be carried out locally. The exploit has been disclosed to the public and may be used. The project was informed of the problem early through an issue report but has not responded yet.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- Technical severity (medium)+3
- CISA SSVC: exploitation "poc"+5
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (MZ Automation libIEC61850).
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Search available logs for exploit probes matching the vulnerability class (memory corruption), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| MZ Automation | libIEC61850 | version 1.6.0version 1.6.1 | Vulnerable | CVE Program (cve.org) e CISA ADP |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 4.8 | CVSS 4.0 | Medium | — | — | VulDB via CVE Program (cve.org) e CISA ADP |
| 1.9 | CVSS 4.0 | Low | — | — | cna@vuldb.com via NIST National Vulnerability Database |
| 5.3 | CVSS 3.1 | Medium | 1.8 | 3.4 | cna@vuldb.com via NIST National Vulnerability Database |
| 5.3 | CVSS 3.1 | Medium | — | — | VulDB via CVE Program (cve.org) e CISA ADP |
| 5.3 | CVSS 3.0 | Medium | — | — | VulDB via CVE Program (cve.org) e CISA ADP |
| 4.3 | CVSS 2.0 | Medium | 3.1 | 6.4 | cna@vuldb.com via NIST National Vulnerability Database |
| 4.3 | CVSS 2.0 | Medium | — | — | VulDB via CVE Program (cve.org) e CISA ADP |
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L (score shown at the top: cna@vuldb.com) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
CWE-119 · Buffer Errors (Improper Restriction of Operations within Memory Bounds)
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
- Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · mz automation/libiec61850
- SSVC assessment updated
- Record published
- CVSS changed · 5.3
- Source status changed · → Deferred
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 15, 2026 – Oct 15, 2026
References
6 on the record
Elsewhere on this site
Related CVEs (same products)
- Medium CVE-2026-19206 MZ Automation libiec61850 ASDU Element sv_subscriber.c SVReceiver_stopThreadless heap-based overflow Aug 7, 2026
- Medium CVE-2026-19108 MZ Automation libiec61850 URCB Revalidation reporting.c deleteDataSetValuesShadowBuffer use after free Aug 6, 2026
- Medium CVE-2026-18583 mz-automation libiec61850 MMS Request mms_mapping.c checkDataSetAccess out-of-bounds Aug 3, 2026
- Medium CVE-2026-18582 mz-automation libiec61850 Report Sending Path reporting.c Reporting_RCBWriteAccessHandler free of memory not on the heap Aug 2, 2026
- Medium CVE-2026-66369 MZ Automation libiec61850 Out-of-bounds Read Jul 30, 2026
- Medium CVE-2026-66364 MZ Automation libiec61850 Out-of-bounds Read Jul 30, 2026
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No FIRST EPSS score.
- No fixed version, patch or mitigation documented.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-19259 is "MZ Automation libiec61850 MMS Protocol Workflow iec61850_common.c MmsMapping_varAccessSpecToObjectReference heap-based overflow", rated Medium. It affects libIEC61850 (MZ Automation); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 5.3 describes technical severity. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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