Quick answers
- Is CVE-2026-69603 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-69603 being exploited in the wild.
- How severe is CVE-2026-69603?
- High severity, with a CVSS score of 8.8, published 8 September 2026.
- Which products and versions are affected?
- Microsoft Windows Hyper-V.
- Is there a fix for CVE-2026-69603?
- 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-2026-69603 attacked?
- It is attacked with local access, in an operating system.
- Am I affected by CVE-2026-69603?
- Check whether you run Microsoft Windows Hyper-V. 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-based buffer overflow exists in Windows Hyper-V that can be triggered by an authorized local attacker to achieve arbitrary code execution. The vulnerability requires local access to the system and authorization to interact with Hyper-V components, but does not require administrator privileges to trigger. A successful exploit could allow an attacker to execute code in the context of the Hyper-V process, potentially leading to system compromise and escape from virtualized environments. Microsoft has released security updates to address this vulnerability.
Affected products
- Microsoft Windows Hyper-V
Timeline
- 2026-09-08: disclosed