# CVE-2026-45466: Microsoft Word heap buffer overflow information disclosure

Source: https://junglewise.ai/threats/cve-2026-45466-microsoft-word-heap-buffer-overflow-information-disclosure  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-06-09. Updated: 2026-06-09  
License: CC BY 4.0 with a link back

CVE-2026-45466 · Severity: low · CVSS 3.3 · Published 2026-06-09

A security vulnerability exists in Microsoft Word that could allow an attacker to access sensitive information on a user's computer. To exploit this, an attacker would typically need to convince a user to open a specially crafted document. While the risk of a full system takeover is low, it could lead to the unauthorized disclosure of private data stored in the computer's memory.

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

## Quick answers

**Is CVE-2026-45466 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-45466 being exploited in the wild.

**How severe is CVE-2026-45466?** Low severity, with a CVSS score of 3.3, published 9 June 2026.

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

**Is there a fix for CVE-2026-45466?** 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-2026-45466 attacked?** It is attacked with local access, in a network appliance.

**Am I affected by CVE-2026-45466?** Check whether you run Microsoft Word. 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 (CWE-122) exists in Microsoft Word. The vulnerability is triggered when the application processes a malformed document, leading to an out-of-bounds memory read. An attacker can exploit this by tricking a user into opening a malicious file, which could result in the disclosure of sensitive information from the process memory. The attack vector is local and requires user interaction (UI:R), with a CVSS base score of 3.3 indicating low impact on confidentiality and no impact on integrity or availability.

## Affected products

- Microsoft Word

## Timeline

- 2026-06-09: disclosed
- 2026-06-09: advisory

## References

- [https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-45466](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-45466)

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