# CVE-2026-80091: Microsoft Office use of uninitialized resource

Source: https://junglewise.ai/threats/cve-2026-80091-microsoft-office-use-of-uninitialized-resource  
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-2026-80091 · Severity: medium · CVSS 6.5 · Published 2026-09-08

Microsoft Office contains a vulnerability where uninitialized resources can be accessed, potentially allowing an attacker on the network to view sensitive information stored in or processed by Office documents. This could expose confidential business data, personal information, or other sensitive content without requiring the attacker to have legitimate access to the system.

Technologies: [Microsoft Office](https://junglewise.ai/threats/technologies/office). Vendors: [Microsoft](https://junglewise.ai/threats/vendors/microsoft).

## Quick answers

**Is CVE-2026-80091 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-80091 being exploited in the wild.

**How severe is CVE-2026-80091?** Medium severity, with a CVSS score of 6.5, published 8 September 2026.

**Which products and versions are affected?** Microsoft Office.

**Is there a fix for CVE-2026-80091?** 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-2026-80091 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-80091?** Check whether you run Microsoft Office. 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

This vulnerability is classified as a use of uninitialized resource issue in Microsoft Office. An attacker on the network can trigger the vulnerability to disclose sensitive information from memory or document contents. The attack requires network connectivity to the affected Office application or system. No exploitation in the wild has been reported as of the advisory date. Microsoft has released security updates to address this issue.

## Affected products

- Microsoft Office

## Timeline

- 2026-09-08: disclosed

## References

- [https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-80091](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-80091)

## Related threats

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- [Microsoft Office heap-based buffer overflow](https://junglewise.ai/threats/cve-2026-122198-heap-based-buffer-overflow-in-microsoft-office-allows-an)
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- [Microsoft Office UI security feature bypass](https://junglewise.ai/threats/cve-2026-119998-product-ui-does-not-warn-user-of-unsafe-actions-in-microsoft)
- [Microsoft Office heap-based buffer overflow](https://junglewise.ai/threats/cve-2026-116717-heap-based-buffer-overflow-in-microsoft-office-allows-an)