# CVE-2026-82943: SOEM buffer over-read via unvalidated device messages

Source: https://junglewise.ai/threats/cve-2026-82943-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-2026-82943 · Severity: medium · CVSS 6.5 · Published 2026-10-26

SOEM is an open-source EtherCAT master library used in industrial automation to control devices over a network. A malicious or compromised device on the EtherCAT network can send specially crafted messages that cause the SOEM master to read sensitive data from its memory, potentially exposing up to 64 KB of confidential information.

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

## Quick answers

**Is CVE-2026-82943 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-82943 being exploited in the wild.

**How severe is CVE-2026-82943?** Medium severity, with a CVSS score of 6.5, published 26 October 2026.

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

**Is there a fix for CVE-2026-82943?** 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-2026-82943 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-82943?** 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 fails to validate length values in device responses against actual buffer boundaries, allowing an attacker-controlled device to trigger an out-of-bounds memory read. The vulnerability requires the attacker to be positioned as a device on the EtherCAT network and does not require authentication or user interaction. An attacker can extract sensitive memory contents from the master process.

## 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 overflow via malformed network messages](https://junglewise.ai/threats/cve-2026-70388-soem-version-2-0-0-and-earlier-contains-vulnerabilities-where-a)