# CVE-2026-56177: Microsoft Windows Server use-after-free privilege escalation

Source: https://junglewise.ai/threats/cve-2026-56177-microsoft-windows-server-use-after-free-privilege-escalation  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-08. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-56177 · Severity: high · CVSS 7.8 · Published 2026-09-08

Windows Server is a foundational operating system used to host enterprise applications and services. A use-after-free vulnerability allows an authenticated local user to execute code with elevated privileges, potentially gaining full control of the server and the business-critical systems it hosts.

Technologies: [Microsoft Windows Server](https://junglewise.ai/threats/technologies/windows-server). Vendors: [Microsoft](https://junglewise.ai/threats/vendors/microsoft).

## Quick answers

**Is CVE-2026-56177 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-56177 being exploited in the wild.

**How severe is CVE-2026-56177?** High severity, with a CVSS score of 7.8, published 8 September 2026.

**Which products and versions are affected?** Microsoft Windows Server.

**Is there a fix for CVE-2026-56177?** 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-2026-56177 attacked?** It is attacked with local access, in an operating system.

**Am I affected by CVE-2026-56177?** Check whether you run Microsoft Windows Server. 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 use-after-free vulnerability in Windows Server allows an authorized local attacker to elevate privileges. The flaw is in memory management where a freed object is accessed again, potentially allowing code execution. Exploitation requires local access and existing authentication; the attacker cannot exploit this remotely. A successful exploit grants the attacker system-level privileges, potentially compromising the entire server and its hosted applications. Microsoft has released security updates to address this issue.

## Affected products

- Microsoft Windows Server

## Timeline

- 2026-09-08: disclosed

## References

- [https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-56177](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-56177)

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