# CVE-2026-55142: Microsoft Office Word numeric truncation information disclosure

Source: https://junglewise.ai/threats/cve-2026-55142-microsoft-office-word-numeric-truncation-information-disclosure  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-07-14. Updated: 2026-07-14  
License: CC BY 4.0 with a link back

CVE-2026-55142 · Severity: medium · CVSS 5.5 · Published 2026-07-14

A security vulnerability exists in Microsoft Word and related Office products that could allow an attacker to access sensitive information. To exploit this, an attacker would typically need to trick a user into opening a specially crafted file on their computer. While this does not allow for full system takeover, it could lead to the unauthorized disclosure of private data stored on the local machine.

Technologies: [Microsoft 365 Apps for Enterprise](https://junglewise.ai/threats/technologies/365-apps-for-enterprise), [Microsoft Office 2019](https://junglewise.ai/threats/technologies/office-2019), [Microsoft Office 365 for Mac](https://junglewise.ai/threats/technologies/office-365-for-mac), [Microsoft Office LTSC 2021](https://junglewise.ai/threats/technologies/office-ltsc-2021), [Microsoft Office LTSC 2024](https://junglewise.ai/threats/technologies/office-ltsc-2024), [Microsoft SharePoint Enterprise Server 2016](https://junglewise.ai/threats/technologies/sharepoint-enterprise-server-2016), [Microsoft SharePoint Server 2019](https://junglewise.ai/threats/technologies/sharepoint-server-2019), [Microsoft SharePoint Server Subscription Edition](https://junglewise.ai/threats/technologies/sharepoint-server-subscription-edition), [Microsoft Word 2016](https://junglewise.ai/threats/technologies/word). Vendors: [Microsoft](https://junglewise.ai/threats/vendors/microsoft).

## Quick answers

**Is CVE-2026-55142 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-55142 being exploited in the wild.

**How severe is CVE-2026-55142?** Medium severity, with a CVSS score of 5.5, published 14 July 2026.

**Which products and versions are affected?** Microsoft 365 Apps for Enterprise 16.0.1 and later affected versions; Microsoft Office 2019 19.0.0 and later affected versions; Microsoft Office 365 for Mac 1.0.0 to 16.111.26071215; Microsoft Office LTSC 2021 16.0.1 and later affected versions; and 5 more.

**Is there a fix for CVE-2026-55142?** 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-2026-55142 attacked?** It is attacked with local access, in a network appliance.

**Am I affected by CVE-2026-55142?** Check whether you run Microsoft 365 Apps for Enterprise, Microsoft Office 2019, Microsoft Office 365 for Mac or one of the others listed 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 numeric truncation error (CWE-197) exists in Microsoft Office Word and SharePoint Server components. The vulnerability is triggered when the application incorrectly handles specific numeric values, potentially leading to an information disclosure. An attacker must rely on user interaction, such as convincing a target to open a malicious document, to execute the exploit locally. Successful exploitation allows the attacker to read sensitive information from the memory or local environment of the affected application. Microsoft has released security updates to address this issue across various versions of Office and SharePoint.

## Affected products

- Microsoft Office Word 2016 16.0.1 to 16.0.5561.1000
- Microsoft Office 2019 19.0.0 and later affected versions
- Microsoft Office LTSC 2021 16.0.1 and later affected versions
- Microsoft Office LTSC 2024 16.0.0 and later affected versions
- Microsoft 365 Apps for Enterprise 16.0.1 and later affected versions
- Microsoft Office 365 for Mac 1.0.0 to 16.111.26071215
- Microsoft SharePoint Enterprise Server 2016 16.0.0 to 16.0.5561.1001
- Microsoft SharePoint Server 2019 16.0.0 to 16.0.10417.20175
- Microsoft SharePoint Server Subscription Edition 16.0.0 to 16.0.19725.20434

## Timeline

- 2026-07-14: disclosed
- 2026-07-14: advisory

## References

- [https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55142](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55142)

## Related threats

- [Out-of-bounds read in Microsoft Office Word allows an unauthorized attacker to disclose information locally.](https://junglewise.ai/threats/cve-2026-70310-out-of-bounds-read-in-microsoft-office-word-allows-an)
- [Microsoft SharePoint cross-site scripting vulnerability](https://junglewise.ai/threats/cve-2026-62826-microsoft-sharepoint-cross-site-scripting-vulnerability)
- [Microsoft SharePoint improper authorization privilege escalation](https://junglewise.ai/threats/cve-2026-58277-microsoft-sharepoint-improper-authorization-privilege-escalation)
- [Microsoft Office out-of-bounds read information disclosure](https://junglewise.ai/threats/cve-2026-56195-microsoft-office-out-of-bounds-read-information-disclosure)
- [Microsoft Office Out-of-bounds Read Information Disclosure](https://junglewise.ai/threats/cve-2026-56192-microsoft-office-out-of-bounds-read-information-disclosure)