Information disclosure via out-of-bounds read
Published Sep 8, 2026 · Updated Sep 10, 2026
Out-of-bounds read in Microsoft Office Word allows remote attackers to disclose information through malicious content. Microsoft has not published the affected Word component, parsing path, or specific input whose bounds are not validated before memory is read. Exploitation requires user interaction, and the documented consequence is limited to disclosure rather than data modification or service interruption.
Summary
What happened
Out-of-bounds read in Microsoft Office Word allows remote attackers to disclose information through malicious content. Microsoft has not published the affected Word component, parsing path, or specific input whose bounds are not validated before memory is read. Exploitation requires user interaction, and the documented consequence is limited to disclosure rather than data modification or service interruption.
The record
- CVE
- CVE-2026-78503
- Published
- Sep 8, 2026
- Updated
- Sep 10, 2026
- Vendor
- Microsoft
- Product
- Microsoft Office LTSC for Mac 2024
- Classifications
- CWE-125
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 8, 2026CVE publishedPublication date reported by the CVE source.
- Sep 10, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=-
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo