# CVE-2026-85877: Microsoft Windows Print Spooler heap-based buffer overflow

Source: https://junglewise.ai/threats/cve-2026-85877-microsoft-windows-print-spooler-heap-based-buffer-overflow  
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-2026-85877 · Severity: high · CVSS 8.8 · Published 2026-09-08

Windows Print Spooler is the system component responsible for managing print jobs and communication with printers across corporate networks. A heap-based buffer overflow vulnerability allows attackers on the network to execute arbitrary code with elevated privileges, potentially leading to complete system compromise, data theft, or deployment of malware.

Technologies: [Microsoft Windows Print Spooler](https://junglewise.ai/threats/technologies/windows-print-spooler), [Microsoft Windows 11 24h2](https://junglewise.ai/threats/technologies/windows-11-24h2). Vendors: [Microsoft](https://junglewise.ai/threats/vendors/microsoft).

## Quick answers

**Is CVE-2026-85877 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-85877 being exploited in the wild.

**How severe is CVE-2026-85877?** High severity, with a CVSS score of 8.8, published 8 September 2026.

**Which products and versions are affected?** Microsoft Windows Print Spooler <UNKNOWN>.

**Is there a fix for CVE-2026-85877?** 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-2026-85877 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-85877?** Check whether you run Microsoft Windows Print Spooler or Microsoft Windows 11 24h2 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 heap-based buffer overflow exists in Windows Print Spooler components, triggered by improper bounds checking on attacker-controlled input. The vulnerability is reachable over the network without authentication, allowing remote code execution with the privileges of the spooler service (typically SYSTEM). An attacker can craft a malicious network request to overflow a heap buffer and hijack execution flow. Patches are available from Microsoft; apply security updates immediately.

## Affected products

- Microsoft Windows Print Spooler <UNKNOWN>

## Timeline

- 2026-09-08: disclosed

## References

- [https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-85877](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-85877)

## Related threats

- [Windows Print Spooler heap overflow privilege escalation](https://junglewise.ai/threats/cve-2026-119950-heap-based-buffer-overflow-in-windows-print-spooler-components)
- [Windows Print Spooler use-after-free remote code execution](https://junglewise.ai/threats/cve-2026-113752-use-after-free-in-windows-print-spooler-components-allows-an)
- [Windows Print Spooler relative path traversal privilege escalation](https://junglewise.ai/threats/cve-2026-112762-relative-path-traversal-in-windows-print-spooler-components)
- [Windows Print Spooler use after free privilege escalation](https://junglewise.ai/threats/cve-2026-105567-use-after-free-in-windows-print-spooler-components-allows-an)
- [Windows Print Spooler path traversal information disclosure](https://junglewise.ai/threats/cve-2026-105531-external-control-of-file-name-or-path-in-windows-print-spooler)