Memory Corruption via FMMU Configuration Table Overflow in SOEM
Key facts
- Attack vector
- Adjacent network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-120 and the CVSS impact.
Summary
RT-Labs AB's SOEM 2.0.0 and earlier contains a memory corruption flaw during device configuration. The software writes configuration data to a fixed-size array without checking the index against its maximum of EC_MAXFMMU entries. A malicious device presenting more than EC_MAXFMMU configuration blocks can force writes past the array boundary, corrupting adjacent memory structures and potentially disrupting later operations. The CVSS 3.1 base score is 6.5 (Medium).
Written with Claude Haiku 5.5 from the sources below · 2026-10-28
Description from the CNA
SOEM version 2.0.0 and earlier contains a vulnerability during device configuration where a malicious device can cause memory corruption. The software writes configuration data to a fixed-size array without checking if the array index exceeds its maximum size of EC_MAXFMMU entries. A device presenting more than EC_MAXFMMU configuration blocks can force writes beyond the array boundary, corrupting adjacent memory structures and potentially disrupting subsequent operations.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
Upgrade SOEM to version 2.0.1, the release that fixes this issue.
Written with Claude Haiku 5.5 from the sources below · 2026-10-28
- Fix · CNA SOEM (RT-Labs AB) Fixed in 2.0.1
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Advisory ·
RT-Labs SOEM — rt-labs.com/wp-content/uploads/2026/10/RRTL-260921-01.pdf
6 records Highest priority Priority LOW 6 LOW
Other records, highest priority first
- TI-2026-80287 Buffer overflow in SOEM CoE SDO multi-segment data transfersPriority LOW 39
- TI-2026-80282 SOEM Memory Corruption via Integer Underflow in Message Length ValidationPriority LOW 37
- TI-2026-80300 Out-of-bounds reads in SOEM frame processing expose memoryPriority LOW 30
Timeline
- 2026-10-26 Threatist record created from CVE-2026-82945
- 2026-10-26 CISA SSVC decision points changed
- 2026-10-26 Priority changed: MEDIUM → LOW
- 2026-10-27 Alias added: GHSA-849v-9xpp-vgfg
References
More RT-Labs vulnerabilities
- TI-2026-82626 Out-of-bounds write when parsing AR Vendor Block requests in RT-Labs P-Net CVSS 4.0CRITICAL 9.3
- TI-2026-82632 Resource exhaustion from RPC sessions kept for unknown interface requests CVSS 4.0HIGH 8.7
- TI-2026-82630 NULL pointer dereference in RT-Labs P-Net on implicit read requests CVSS 4.0HIGH 8.7
- TI-2026-82627 NULL pointer dereference in P-Net lets remote attackers crash devices CVSS 4.0HIGH 8.7
- TI-2026-82625 Infinite loop in RT-Labs P-Net PDPortDataCheck record handling CVSS 4.0HIGH 8.7
- TI-2025-23482 Out-of-bounds write in RT-Labs P-Net CVSS 3.1CRITICAL 9.8
Sources
- CVE-2026-82945 · CVE Program
- CVE-2026-82945 · NVD
- FIRST EPSS
- GHSA-849v-9xpp-vgfg · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences