Information Disclosure Vulnerability in Microsoft Office Word by Microsoft
CVE-2026-78503

6.5MEDIUM

Key Information:

Vendor

Microsoft
Status
Microsoft 365 Apps For Enterprise
Microsoft Office 2019
Microsoft Office 365 For Mac
Microsoft Office Ltsc 2021
Vendor
CVE Published:
8 September 2026

What is CVE-2026-78503?

An information disclosure vulnerability in Microsoft Office Word could allow an unauthorized attacker to read sensitive information through an out-of-bounds read. This could potentially lead to sensitive data exposure over a network, undermining the security of the affected systems. Microsoft has issued a patch to address this vulnerability and recommends updating affected versions to mitigate risks.

Affected Version(s)

Microsoft 365 Apps for Enterprise 32-bit Systems 16.0.1 < 16.0.20326.20138

Microsoft Office 2019 32-bit Systems 19.0.0 < 16.0.10417.20207

Microsoft Office 365 for Mac -

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE...
vendor-advisorypatch

CVSS V3.1

Score:
6.5
Severity:
MEDIUM
Confidentiality:
High
Integrity:
None
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
Required
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.