Quick answers
- Is CVE-2026-63033 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-63033 being exploited in the wild.
- How severe is CVE-2026-63033?
- Medium severity, with a CVSS score of 6.5, published 30 July 2026.
- Which products and versions are affected?
- MZ Automation Lib60870 2.4.0.
- Is there a fix for CVE-2026-63033?
- A patch was published on 2026-07-30: Version 2.4.1 released to address the issue Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-63033 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-63033?
- 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
An out-of-bounds read (CWE-125) exists in the InformationObject_ParseObjectAddress function within cs101_information_objects.c. The vulnerability is caused by a lack of bounds checking on the msgSize parameter when processing the Variable Structure Qualifier (VSQ) field in an IEC 60870-5-104 I-frame. If the declared object count exceeds the actual ASDU body size, the function reads one byte past the end of the heap-allocated message buffer. This can be exploited remotely over TCP port 2404 without authentication. The issue was identified via fuzzing and is addressed in version 2.4.1.
Affected products
- MZ Automation lib60870 2.4.0
Timeline
- 2026-06-05: advisory: Vendor advisory GHSA-7v97-jmwv-w5j7 published
- 2026-07-30: disclosed: CISA Advisory ICSA-26-211-11 published
- 2026-07-30: patched: Version 2.4.1 released to address the issue