Quick answers
- Is CVE-2026-55038 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-55038 being exploited in the wild.
- How severe is CVE-2026-55038?
- High severity, with a CVSS score of 7.8, published 14 July 2026.
- Which products and versions are affected?
- Microsoft Word Microsoft 365 Apps, Office 2019, Office LTSC 2021/2024, SharePoint Server.
- Is there a fix for CVE-2026-55038?
- 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-2026-55038 attacked?
- It is attacked with local access, in a network appliance.
- Am I affected by CVE-2026-55038?
- Check whether you run Microsoft SharePoint Server or Microsoft 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
A stack-based buffer overflow (CWE-121) exists in Microsoft Office Word. The vulnerability is triggered when the application fails to properly validate input while parsing a document, leading to memory corruption. An attacker can exploit this by convincing a target user to open a malicious Word document. Successful exploitation allows for arbitrary code execution in the context of the current user. The attack vector is local with a requirement for user interaction (UI:R). Microsoft has released security updates to address this issue across affected versions of Office and SharePoint Server.
Affected products
- Microsoft Office Word Microsoft 365 Apps, Office 2019, Office LTSC 2021/2024, SharePoint Server
Timeline
- 2026-07-14: disclosed
- 2026-07-14: advisory: Microsoft published the security update guide.