# CVE-2026-12661: Rockwell Automation FactoryTalk Historian Machine Edition stack-based buffer overflow

Source: https://junglewise.ai/threats/cve-2026-12661-rockwell-automation-factorytalk-historian-machine-edition-stack  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-01. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-12661 · Severity: info · CVSS 4.5 · Published 2026-09-01

FactoryTalk Historian Machine Edition is an embedded data historian module used in industrial automation systems to collect and store time-series process data. An authenticated network-adjacent attacker can exploit a stack-based buffer overflow in the web interface by sending crafted requests, causing the device to crash and become temporarily unavailable, disrupting machine-level data collection and monitoring operations.

Vendors: [Rockwell Automation](https://junglewise.ai/threats/vendors/rockwell-automation).

## Quick answers

**Is CVE-2026-12661 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-12661 being exploited in the wild.

**How severe is CVE-2026-12661?** Informational severity, with a CVSS score of 4.5, published 1 September 2026.

**Which products and versions are affected?** Rockwell Automation FactoryTalk Historian Machine Edition Series B 5.202, Series C 7.101.

**Is there a fix for CVE-2026-12661?** 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-2026-12661 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-12661?** Check whether you run Rockwell Automation FactoryTalk Historian Machine Edition 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

This vulnerability is a stack-based buffer overflow (CWE-121) in FactoryTalk Historian Machine Edition's web interface. An attacker with low-level authentication credentials and network adjacency can send specially crafted requests that trigger the overflow condition. The overflow causes a denial-of-service condition, crashing the device and making it unresponsive until manually recovered. The vulnerability affects Historian ME Series B (version 5.202) and Series C (version 7.101), with fixes available in Series B version 5.203 and Series C version 7.102. No public exploit code is known, and patches are available.

## Affected products

- Rockwell Automation FactoryTalk Historian Machine Edition Series B 5.202, Series C 7.101

## Timeline

- 2026-09-01: disclosed: Security advisory SD1796 published

## References

- [https://www.rockwellautomation.com/en-us/trust-center/security-advisories/advisory.SD1796.html](https://www.rockwellautomation.com/en-us/trust-center/security-advisories/advisory.SD1796.html)

## Related threats

- [Rockwell Automation FactoryTalk Historian Machine Edition out-of-bounds write](https://junglewise.ai/threats/cve-2025-12768-rockwell-automation-factorytalk-historian-machine-edition-out-of)