# CVE-2026-78514: Microsoft Office Word use-after-free remote code execution

Source: https://junglewise.ai/threats/cve-2026-78514-microsoft-office-word-use-after-free-remote-code-execution  
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-2026-78514 · Severity: high · CVSS 8.8 · Published 2026-09-08

Microsoft Office Word contains a use-after-free vulnerability that could allow an attacker to execute arbitrary code on a user's system through a specially crafted Word document. If exploited, an attacker could gain control over the user's computer, access sensitive documents, or deploy malware. The vulnerability requires user interaction (opening a malicious document) but has a high severity rating.

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

## Quick answers

**Is CVE-2026-78514 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-78514 being exploited in the wild.

**How severe is CVE-2026-78514?** High severity, with a CVSS score of 8.8, published 8 September 2026.

**Which products and versions are affected?** Microsoft Office Word <UNKNOWN>.

**Is there a fix for CVE-2026-78514?** 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-2026-78514 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-78514?** Check whether you run Microsoft Office Word 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

This vulnerability is a use-after-free memory corruption flaw in Microsoft Office Word. The vulnerability allows remote code execution when a user opens a maliciously crafted Word document. The attack vector is network-based, requiring user interaction to open the document; no prior authentication is needed. Successful exploitation grants an attacker arbitrary code execution in the context of the user running Word. Microsoft has released a security update to address this issue, as indicated by the official Security Update Guide reference.

## Affected products

- Microsoft Office Word <UNKNOWN>

## Timeline

- 2026-09-08: disclosed

## References

- [https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-78514](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-78514)

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