Quick answers
- Is CVE-2026-51219 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-51219 being exploited in the wild.
- How severe is CVE-2026-51219?
- Informational severity, with a CVSS score of 7.5, published 29 June 2026.
- Which products and versions are affected?
- MZ Automation Lib60870 2.3.3 to 2.3.6.
- Is there a fix for CVE-2026-51219?
- 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-2026-51219 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-51219?
- Check whether you run MZ Automation Lib60870 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
A heap buffer overflow exists in the CS104 server-side implementation of lib60870. The vulnerability is caused by a format mismatch in the high-priority ASDU queue: while HighPriorityASDUQueue_enqueue stores entries as a 16-bit size followed by raw bytes, HighPriorityASDUQueue_hasUnconfirmedIMessages traverses the queue as if entries begin with a metadata structure (sMessageQueueEntryInfo). This inconsistency leads to the misinterpretation of payload bytes as metadata, causing the traversal logic to read past the allocated buffer. An unauthenticated remote attacker can exploit this by sending crafted IEC 60870-5-104 messages to trigger a crash (Denial of Service). The issue was identified in version 2.3.6 and affects versions back to 2.3.3.
Affected products
- MZ Automation lib60870 2.3.3 to 2.3.6
Timeline
- 2026-06-29: disclosed: Vulnerability disclosed via NVD and GitHub issue.
- 2026-06-29: advisory