Quick answers
- Is CVE-2026-71338 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-71338 being exploited in the wild.
- How severe is CVE-2026-71338?
- Medium severity, with a CVSS score of 6.4, published 8 September 2026.
- Which products and versions are affected?
- Microsoft Windows Failover Cluster <UNKNOWN>.
- Is there a fix for CVE-2026-71338?
- 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-2026-71338 attacked?
- It is attacked with local access, in an operating system.
- Am I affected by CVE-2026-71338?
- Check whether you run Microsoft Windows Failover Cluster 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 double-free vulnerability exists in Windows Failover Cluster where memory is freed twice in certain code paths, potentially leading to heap corruption and code execution. The vulnerability requires prior authentication/authorization to trigger, as it can only be exploited by an authorized local attacker with existing access to the system. The attack vector is local; it does not require network access. Successful exploitation allows privilege escalation from the attacker's current user context to a higher privilege level. Microsoft has issued a security patch to resolve this issue.
Affected products
- Microsoft Windows Failover Cluster <UNKNOWN>
Timeline
- 2026-09-08: disclosed