Double free in libIEC61850 MMS ObtainFile handling
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · None · Low
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA.
Summary
libIEC61850 from 1.6.1 before 1.6.2 is affected. A successful MMS ObtainFile operation closes a file handle but leaves its stale value in a reusable task, so a later ObtainFile request that reuses the task and fails while creating the destination closes the same file again (CWE-415). A remote, unauthenticated attacker can crash servers that enable the MMS file service and ObtainFile by triggering this cleanup path.
Written with Claude Haiku 5.5 from the sources below · 2026-10-29
Description from the CNA
libIEC61850 is an open-source implementation of IEC 61850 client and server protocols including MMS, GOOSE, Sampled Values, and R-Session. From 1.6.1 until 1.6.2, a successful MMS ObtainFile operation closes MmsObtainFileTask::fileHandle but leaves the stale non-NULL value in a task marked MMS_FILE_UPLOAD_STATE_NOT_USED. If a later ObtainFile request reuses that task and destination creation fails, MMS_FILE_UPLOAD_STATE_SEND_OBTAIN_FILE_ERROR_DESTINATION cleanup closes the stale FILE object again. Servers with the MMS file service and ObtainFile enabled can therefore be crashed remotely by the success-then-failure request sequence. This issue is fixed in version 1.6.2.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| MZ Automation | libiec61850 | 1.6.1 to before 1.6.2 | 1.6.2 | Patch available | CNA |
- libiec61850 VendorMZ Automation Affected 1.6.1 to before 1.6.2 Fixed in 1.6.2 Patch available CNA
CPE names Threatist (inferred) · 1
Inferred from how NVD named this product before; not given by a source.
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:mz-automation:libiec61850:*:*:*:*:*:*:*:* | — | — | MZ Automation |
- cpe:2.3:a:mz-automation:libiec61850:*:*:*:*:*:*:*:* Versions — — ·MZ Automation
Remediation
The fix is in libiec61850 version 1.6.2.
Written with Claude Haiku 5.5 from the sources below · 2026-10-29
- Fix · CNA libiec61850 (mz-automation) Fixed in 1.6.2
Timeline
- 2026-10-16 Threatist record created from CVE-2026-57446
- 2026-10-28 CISA SSVC decision points changed
- 2026-10-28 Priority changed: LOW → MEDIUM
References
More MZ Automation vulnerabilities
- TI-2026-75355 Infinite loop and out-of-bounds read in libIEC61850 ACSE parsing CVSS 4.0HIGH 8.7
- TI-2026-75345 Remote NULL dereference in libIEC61850 MMS Read crashes servers CVSS 3.1HIGH 7.5
- TI-2026-75344 Remote information disclosure in libIEC61850 MMS file service CVSS 3.1HIGH 7.5
- TI-2024-18824 In mz-automation libiec61850 v1.4.0, a NULL Pointer Dereference was detected in the… CVSS 3.1HIGH 7.5
- TI-2022-05561 Infinite loop in MZ Automation libiec61850 CVSS 3.1HIGH 7.5
- TI-2026-45011 MZ Automation lib60870 Out-of-bounds Read CVSS 4.0MEDIUM 6.9
Sources
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences