# CVE-2026-70388: SOEM buffer overflow via malformed network messages

Source: https://junglewise.ai/threats/cve-2026-70388-soem-version-2-0-0-and-earlier-contains-vulnerabilities-where-a  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-26. Updated: 2026-10-26  
License: CC BY 4.0 with a link back

CVE-2026-70388 · Severity: high · CVSS 8.3 · Published 2026-10-26

SOEM is an EtherCAT master library used in industrial automation systems. A malicious device on the network can send specially crafted EtherCAT messages that cause the master to write data outside allocated memory, potentially corrupting critical system memory and enabling arbitrary code execution.

Technologies: [RT-Labs SOEM](https://junglewise.ai/threats/technologies/soem). Vendors: [RT-Labs](https://junglewise.ai/threats/vendors/rt-labs).

## Quick answers

**Is CVE-2026-70388 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-70388 being exploited in the wild.

**How severe is CVE-2026-70388?** High severity, with a CVSS score of 8.3, published 26 October 2026.

**Which products and versions are affected?** RT-Labs SOEM 2.0.0 and earlier.

**Is there a fix for CVE-2026-70388?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-70388 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-70388?** Check whether you run RT-Labs SOEM at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

SOEM version 2.0.0 and earlier improperly validates message length values in incoming EtherCAT frames, allowing negative or extremely large values to bypass bounds checks. An attacker with network access can craft messages that trigger out-of-bounds memory writes on the master system, leading to memory corruption and potentially arbitrary code execution.

## Affected products

- RT-Labs SOEM 2.0.0 and earlier

## Timeline

- 2026-10-26: disclosed

## References

- [https://rt-labs.com/wp-content/uploads/2026/10/RRTL-260921-01.pdf](https://rt-labs.com/wp-content/uploads/2026/10/RRTL-260921-01.pdf)

## Related threats

- [SOEM buffer over-read in frame processing](https://junglewise.ai/threats/cve-2026-82947-soem-version-2-0-0-and-earlier-contains-multiple-vulnerabilities)
- [SOEM use-after-free in message handling](https://junglewise.ai/threats/cve-2026-82946-soem-version-2-0-0-and-earlier-contains-a-vulnerability-where-a)
- [SOEM buffer overflow in device configuration](https://junglewise.ai/threats/cve-2026-82945-soem-version-2-0-0-and-earlier-contains-a-vulnerability-during)
- [SOEM multi-segment data transfer buffer overflow](https://junglewise.ai/threats/cve-2026-82944-soem-version-2-0-0-and-earlier-contains-a-vulnerability-in-multi)
- [SOEM buffer over-read via unvalidated device messages](https://junglewise.ai/threats/cve-2026-82943-soem-version-2-0-0-and-earlier-contains-vulnerabilities-where-a)