# CVE-2026-80087: Microsoft Office heap-based buffer overflow

Source: https://junglewise.ai/threats/cve-2026-80087-microsoft-office-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-2026-80087 · Severity: medium · CVSS 6.5 · Published 2026-09-08

Microsoft Office is a suite of productivity applications widely used in enterprises for document creation and collaboration. A heap-based buffer overflow vulnerability allows attackers to disclose sensitive information by sending specially crafted files over a network, potentially exposing corporate data without requiring user credentials or permissions.

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

## Quick answers

**Is CVE-2026-80087 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-80087 being exploited in the wild.

**How severe is CVE-2026-80087?** 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-2026-80087?** 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-2026-80087 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-80087?** 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

A heap-based buffer overflow exists in Microsoft Office when processing malformed input. An attacker can exploit this vulnerability by crafting and delivering a malicious file over the network that triggers the overflow condition in memory, leading to information disclosure. The vulnerability is remotely exploitable over a network vector and does not require authentication or special user interaction. While no active exploitation in the wild has been reported, the ability to leak sensitive data from memory makes this a notable risk for organizations.

## Affected products

- Microsoft Office

## Timeline

- 2026-09-08: disclosed

## References

- [https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-80087](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-80087)

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