Quick answers
- Is CVE-2026-85440 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-85440 being exploited in the wild.
- How severe is CVE-2026-85440?
- Critical severity, with a CVSS score of 9.8, published 3 September 2026.
- Which products and versions are affected?
- MOOS Core-Moos through 10.4.0.
- Is there a fix for CVE-2026-85440?
- 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-2026-85440 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-85440?
- Check whether you run MOOS Core-Moos 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
The vulnerability is a pre-authentication heap buffer overflow in the MOOSCommPkt packet handler, specifically in the InflateTo() and recv() functions. An attacker can craft a malicious packet with a negative length value that bypasses signed integer checks and causes a four-byte heap buffer to overflow during the HandShake phase before any authentication occurs. This occurs because the negative size declaration is not properly validated before being used in memory operations. The overflow permits arbitrary data write and can lead to remote code execution. The vulnerability affects core-moos through version 10.4.0, and a patch is required.
Affected products
- MOOS core-moos through 10.4.0
Timeline
- 2026-09-03: disclosed